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This article is about the concept of nous or intellect in philosophy. See also Intelligence (disambiguation)
Intelligence (disambiguation)
Intelligence is a term describing one or more capacities of the mind.Intelligence may also refer to:* Intelligence assessment - for example espionage* Military intelligence...

 and Intellect (disambiguation)
Intellect (disambiguation)
Intellect is a term used in studies of the human mind. This may also refer to these related topics:* A philosophical and cosmological term with Latin origins, which is equivalent to Greek nous...

.


Nous (British: icon; US: ˈ), also called intellect
Intellect
Intellect is a term used in studies of the human mind, and refers to the ability of the mind to come to correct conclusions about what is true or real, and about how to solve problems...

or intelligence
Intelligence
Intelligence has been defined in different ways, including the abilities for abstract thought, understanding, communication, reasoning, learning, planning, emotional intelligence and problem solving....

, is a philosophical term for the faculty of the human mind which is described in classical philosophy as necessary for understanding what is true
Truth
Truth has a variety of meanings, such as the state of being in accord with fact or reality. It can also mean having fidelity to an original or to a standard or ideal. In a common usage, it also means constancy or sincerity in action or character...

 or real
Reality
In philosophy, reality is the state of things as they actually exist, rather than as they may appear or might be imagined. In a wider definition, reality includes everything that is and has been, whether or not it is observable or comprehensible...

, very close in meaning to intuition
Intuition (philosophy)
Intuition is a priori knowledge or experiential belief characterized by its immediacy. Beyond this, the nature of intuition is debated. Roughly speaking, there are two main views. They are:...

. It is also often described as a form of perception
Perception
Perception is the process of attaining awareness or understanding of the environment by organizing and interpreting sensory information. All perception involves signals in the nervous system, which in turn result from physical stimulation of the sense organs...

 which works within the mind ("the mind's eye
Mind's eye
The phrase "mind's eye" refers to the human ability for visualization, i.e., for the experiencing of visual mental imagery; in other words, one's ability to "see" things with the mind.- Physical basis :...

"), rather than only through the physical senses. The three commonly used philosophical terms are from Greek
Ancient Greek
Ancient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being predated in the 2nd millennium BC by Mycenaean Greek...

, νοῦς or , and Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

 intellectus and intelligentia respectively.

In philosophy
Philosophy
Philosophy is the study of general and fundamental problems, such as those connected with existence, knowledge, values, reason, mind, and language. Philosophy is distinguished from other ways of addressing such problems by its critical, generally systematic approach and its reliance on rational...

, common English translations include "understanding
Understanding
Understanding is a psychological process related to an abstract or physical object, such as a person, situation, or message whereby one is able to think about it and use concepts to deal adequately with that object....

" and "mind
Mind
The concept of mind is understood in many different ways by many different traditions, ranging from panpsychism and animism to traditional and organized religious views, as well as secular and materialist philosophies. Most agree that minds are constituted by conscious experience and intelligent...

"; or sometimes "reason
Reason
Reason is a term that refers to the capacity human beings have to make sense of things, to establish and verify facts, and to change or justify practices, institutions, and beliefs. It is closely associated with such characteristically human activities as philosophy, science, language, ...

" and "thought
Thought
"Thought" generally refers to any mental or intellectual activity involving an individual's subjective consciousness. It can refer either to the act of thinking or the resulting ideas or arrangements of ideas. Similar concepts include cognition, sentience, consciousness, and imagination...

". To describe the activity of this faculty, apart from verbs based on "understanding", the verb "intellection" is sometimes used in philosophical contexts, and the Greek words noēsis and noein are sometimes also used. In colloquial British English
British English
British English, or English , is the broad term used to distinguish the forms of the English language used in the United Kingdom from forms used elsewhere...

, nous denotes "common sense
Common sense
Common sense is defined by Merriam-Webster as, "sound and prudent judgment based on a simple perception of the situation or facts." Thus, "common sense" equates to the knowledge and experience which most people already have, or which the person using the term believes that they do or should have...

", which is close to its original everyday meaning in Ancient Greece
Ancient Greece
Ancient Greece is a civilization belonging to a period of Greek history that lasted from the Archaic period of the 8th to 6th centuries BC to the end of antiquity. Immediately following this period was the beginning of the Early Middle Ages and the Byzantine era. Included in Ancient Greece is the...

.

Apart from referring to a faculty of the human mind, this philosophical concept has often been extended to describe the source of order in nature
Nature (philosophy)
Nature is a concept with two major sets of inter-related meanings, referring on the one hand to the things which are natural, or subject to the normal working of "laws of nature", or on the other hand to the essential properties and causes of those things to be what they naturally are, or in other...

 itself.

Introduction: nous in philosophy


The basic meaning of "nous" or "intellect" is "understanding", but several sources or types of "understandings" are often distinguished from each other:
  • Sense
    Sense
    Senses are physiological capacities of organisms that provide inputs for perception. The senses and their operation, classification, and theory are overlapping topics studied by a variety of fields, most notably neuroscience, cognitive psychology , and philosophy of perception...

     perception is a source of feelings, impressions, or raw data about things, but it needs to be interpreted in order for there to be converted into real understanding.
  • Reason
    Reason
    Reason is a term that refers to the capacity human beings have to make sense of things, to establish and verify facts, and to change or justify practices, institutions, and beliefs. It is closely associated with such characteristically human activities as philosophy, science, language, ...

     is a source of new understandings but it is built by putting together and distinguishing other things already understood.

Philosophical discussion of nous has therefore centred around the origin of the most basic understandings which allow people to make sense of what they see, hear, taste or feel, and which also allow them to start reasoning. These basic understandings are often felt to at least include such things as understandings of geometrical and logical basics, and also an ability to generalize properly into correct categories
Categorization
Categorization is the process in which ideas and objects are recognized, differentiated and understood. Categorization implies that objects are grouped into categories, usually for some specific purpose. Ideally, a category illuminates a relationship between the subjects and objects of knowledge...

 or universals, setting definitions. This mental step between perception and reasoning has sometimes been discussed as an aspect of perception or an aspect of reasoning, as will be seen below.

The question then also arose of whether there can really be any source of such basic understanding other than the accumulation of perceptions. Somehow the human mind sets definitions in a consistent way, because people perceive the same things and can discuss them. So the argument goes, as will be shown below, that people must be born with some innate potential to understand the same things the same ways. And in addition to this it has also been argued that this possibility must require help of a spiritual and divine type. The question of where understanding comes from, is therefore related to the question of what knowledge
Knowledge
Knowledge is a familiarity with someone or something unknown, which can include information, facts, descriptions, or skills acquired through experience or education. It can refer to the theoretical or practical understanding of a subject...

 is, and how things can and should be defined or classified.

Another important philosophical discussion concerning nous stemming from these, involves not only human thinking, but the nature of the cosmos
Cosmos
In the general sense, a cosmos is an orderly or harmonious system. It originates from the Greek term κόσμος , meaning "order" or "ornament" and is antithetical to the concept of chaos. Today, the word is generally used as a synonym of the word Universe . The word cosmos originates from the same root...

 itself. As mentioned above, some philosophers proposed that the human mind must have an ability to understand which is divine, and independent of normal sense experience and physics. This ordering of the individual human mind, it is then argued, must be somehow derived from a cosmic mind which orders nature just like the human mind orders its understanding of nature. This was claimed from an early time, by Greek philosophers such as Anaxagoras
Anaxagoras
Anaxagoras was a Pre-Socratic Greek philosopher. Born in Clazomenae in Asia Minor, Anaxagoras was the first philosopher to bring philosophy from Ionia to Athens. He attempted to give a scientific account of eclipses, meteors, rainbows, and the sun, which he described as a fiery mass larger than...

. By this type of account, it came to be argued that the human understanding (nous) somehow stems from this cosmic nous, which is however not just a recipient of order, but a creator of it. Such explanations were influential in the development of medieval accounts of God
God
God is the English name given to a singular being in theistic and deistic religions who is either the sole deity in monotheism, or a single deity in polytheism....

, the immortality of the soul, and even the motions of the stars
Celestial spheres
The celestial spheres, or celestial orbs, were the fundamental entities of the cosmological models developed by Plato, Eudoxus, Aristotle, Ptolemy, Copernicus and others...

, in Europe, North Africa and the Middle East, amongst both eclectic philosophers and authors representing all the major faiths of their times.

Pre-Socratic usage



In early Greek uses, Homer
Homer
In the Western classical tradition Homer , is the author of the Iliad and the Odyssey, and is revered as the greatest ancient Greek epic poet. These epics lie at the beginning of the Western canon of literature, and have had an enormous influence on the history of literature.When he lived is...

 used nous to signify mental activities of both mortal
Human
Humans are the only living species in the Homo genus...

s and immortals, for example what they really have on their mind as opposed to what they say aloud. It was one of several words related to thought, thinking, and perceiving with the mind. Amongst pre-Socratic philosophers it became increasingly distinguished as a source of knowledge and reasoning and opposed to mere sense perception, or thinking influenced by the body such as emotion. For example Heraclitus
Heraclitus
Heraclitus of Ephesus was a pre-Socratic Greek philosopher, a native of the Greek city Ephesus, Ionia, on the coast of Asia Minor. He was of distinguished parentage. Little is known about his early life and education, but he regarded himself as self-taught and a pioneer of wisdom...

 complained that "much learning does not teach nous".

Among some Greek authors a faculty of intelligence, a "higher mind", came to be considered to be a property of the cosmos as a whole.

The work of Parmenides of Elea set the scene for Greek philosophy to come and the concept of nous was central to his radical proposals. He claimed that reality as the senses perceive it is not a world of truth at all, because sense perception is so unreliable, and what is perceived is so uncertain and changeable. Instead he argued for a dualism wherein nous and related words (the verb for thinking which describes its mental perceiving activity, noein, and the unchanging and eternal objects of this perception noēta) describe a form of perception which is not physical, but intellectual only, distinct from sense perception and the objects of sense perception. These eternal immaterial objects which people perceive in their mind are the equivalent of the forms or ideas, in the later philosophy of Plato and Aristotle.

Anaxagoras of Clazomenae, born about 500 BC, is the first person who is definitely known to have explained the concept of a nous (mind), which arranged all other things in the cosmos in their proper order, started them in a rotating motion, and continuing to control them to some extent, having an especially strong connection with living things. (However Aristotle reports an earlier philosopher from Clezomenae named of Hermotimus
Hermotimus of Clazomenae
Hermotimus of Clazomenae , called by Lucian a Pythagorean, was a philosopher who first proposed, before Anaxagoras the idea of mind being fundamental in the cause of change. He proposed that physical entities are static, while the mind causes the change...

 who had taken a similar position.) Amongst Pre-Socratic philosophers before Anaxagoras, other philosophers had proposed a similar ordering human-like principle causing life and the rotation of the heavens. For example Empedocles
Empedocles
Empedocles was a Greek pre-Socratic philosopher and a citizen of Agrigentum, a Greek city in Sicily. Empedocles' philosophy is best known for being the originator of the cosmogenic theory of the four Classical elements...

, like Hesiod
Hesiod
Hesiod was a Greek oral poet generally thought by scholars to have been active between 750 and 650 BC, around the same time as Homer. His is the first European poetry in which the poet regards himself as a topic, an individual with a distinctive role to play. Ancient authors credited him and...

 much earlier, described cosmic order and living things as caused by a cosmic version of love
Love
Love is an emotion of strong affection and personal attachment. In philosophical context, love is a virtue representing all of human kindness, compassion, and affection. Love is central to many religions, as in the Christian phrase, "God is love" or Agape in the Canonical gospels...

, and Pythagoras
Pythagoras
Pythagoras of Samos was an Ionian Greek philosopher, mathematician, and founder of the religious movement called Pythagoreanism. Most of the information about Pythagoras was written down centuries after he lived, so very little reliable information is known about him...

 and Heraclitus, attributed the cosmos with "reason" (logos
Logos
' is an important term in philosophy, psychology, rhetoric and religion. Originally a word meaning "a ground", "a plea", "an opinion", "an expectation", "word," "speech," "account," "reason," it became a technical term in philosophy, beginning with Heraclitus ' is an important term in...

).

According to Anaxagoras the cosmos
Cosmos
In the general sense, a cosmos is an orderly or harmonious system. It originates from the Greek term κόσμος , meaning "order" or "ornament" and is antithetical to the concept of chaos. Today, the word is generally used as a synonym of the word Universe . The word cosmos originates from the same root...

 is made of infinitely divisible matter, every bit of which can inherently become anything, except Mind (nous), which is also matter, but which can only be found separated from this general mixture, or else mixed in to living things, or in other words in the Greek terminology of the time, things with a soul (psuchē). Anaxagoras wrote:
Concerning cosmology
Cosmology
Cosmology is the discipline that deals with the nature of the Universe as a whole. Cosmologists seek to understand the origin, evolution, structure, and ultimate fate of the Universe at large, as well as the natural laws that keep it in order...

, Anaxagoras, like some Greek philosophers already before him, believed the cosmos was revolving, and had formed into its visible order as a result of such revolving causing a separating and mixing of different types of elements. Nous, in his system, originally caused this revolving motion to start, but it does not necessarily continue to play a role once the mechanical motion has started. His description was in other words (shockingly for the time) corporeal or mechanical, with the moon
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...

 made of earth, the sun and stars made of red hot metal (beliefs Socrates was later accused of holding during his trial) and nous itself being a physical fine type of matter which also gathered and concentrated with the development of the cosmos. This nous (mind) is not incorporeal; it is the thinnest of all things. The distinction between nous and other things nevertheless causes his scheme to sometimes be described as a peculiar kind of dualism.

Anaxagoras' concept of nous was distinct from later platonic and neoplatonic cosmologies in many ways, which were also influenced by Eleatic, Pythagorean
Pythagoreanism
Pythagoreanism was the system of esoteric and metaphysical beliefs held by Pythagoras and his followers, the Pythagoreans, who were considerably influenced by mathematics. Pythagoreanism originated in the 5th century BCE and greatly influenced Platonism...

 and other pre Socratic ideas, as well as the Socratics themselves.

In ancient Indian Philosophy
Indian philosophy
India has a rich and diverse philosophical tradition dating back to ancient times. According to Radhakrishnan, the earlier Upanisads constitute "...the earliest philosophical compositions of the world."...

 also, a "higher mind", came to be considered to be a property of the cosmos as a whole.

Xenophon


Xenophon
Xenophon
Xenophon , son of Gryllus, of the deme Erchia of Athens, also known as Xenophon of Athens, was a Greek historian, soldier, mercenary, philosopher and a contemporary and admirer of Socrates...

, the less famous of the two students of Socrates whose written accounts of him have survived, recorded that he taught his students a kind of teleological justification of piety and respect for divine order in nature. This has been described as an "intelligent design
Intelligent design
Intelligent design is the proposition that "certain features of the universe and of living things are best explained by an intelligent cause, not an undirected process such as natural selection." It is a form of creationism and a contemporary adaptation of the traditional teleological argument for...

" argument for the existence of God, in which nature has its own nous. For example in his Memorabilia
Memorabilia (Xenophon)
Memorabilia is a collection of Socratic dialogues by Xenophon, a student of Socrates...

1.4.8 he describes Socrates asking a friend sceptical of religion "Are you, then, of the opinion that intelligence (nous) alone exists nowhere and that you by some good chance seized hold of it, while - as you think - those surpassingly large and infinitely numerous things [all the earth and water] are in such orderly condition through some senselessness?" and later in the same discussion he compares the nous which directs each person's body, to the good sense (phronēsis
Phronesis
Phronēsis is an Ancient Greek word for wisdom or intelligence which is a common topic of discussion in philosophy. In Aristotelian Ethics, for example in the Nicomachean Ethics it is distinguished from other words for wisdom as the virtue of practical thought, and is usually translated "practical...

) of the god which is in everything, arranging things to its pleasure. (1.4.17). Plato describes Socrates making the same argument in his Philebus
Philebus
The Philebus , composed between 360 and 347 BC, is among the last of the late Socratic dialogues of the ancient Greek philosopher Plato. Socrates is the primary speaker in Philebus, unlike in the other late dialogues...

28d, using the same words nous and phronēsis.

Plato


Plato
Plato
Plato , was a Classical Greek philosopher, mathematician, student of Socrates, writer of philosophical dialogues, and founder of the Academy in Athens, the first institution of higher learning in the Western world. Along with his mentor, Socrates, and his student, Aristotle, Plato helped to lay the...

 used the word nous in many ways which were not unusual in the everyday Greek of the time, and often simply meant "good sense". On the other hand, in some of his dialogues it is described by key characters in a higher sense, which was apparently already common. In his Philebus
Philebus
The Philebus , composed between 360 and 347 BC, is among the last of the late Socratic dialogues of the ancient Greek philosopher Plato. Socrates is the primary speaker in Philebus, unlike in the other late dialogues...

28c he has Socrates say that "all philosophers agree—whereby they really exalt themselves—that mind (nous) is king of heaven and earth. Perhaps they are right." and later states that the ensuing discussion "confirms the utterances of those who declared of old that mind (nous) always rules the universe".

In his Cratylus
Cratylus (dialogue)
Cratylus is the name of a dialogue by Plato. Most modern scholars agree that it was written mostly during Plato's so-called middle period...

, Plato gives the etymology
Etymology
Etymology is the study of the history of words, their origins, and how their form and meaning have changed over time.For languages with a long written history, etymologists make use of texts in these languages and texts about the languages to gather knowledge about how words were used during...

 of Athena
Athena
In Greek mythology, Athena, Athenê, or Athene , also referred to as Pallas Athena/Athene , is the goddess of wisdom, courage, inspiration, civilization, warfare, strength, strategy, the arts, crafts, justice, and skill. Minerva, Athena's Roman incarnation, embodies similar attributes. Athena is...

's name, the goddess of wisdom, from Atheonóa (Ἀθεονόα) from god's (theos) mind (nous). In his Phaedo
Phaedo
Plato's Phaedo is one of the great dialogues of his middle period, along with the Republic and the Symposium. The Phaedo, which depicts the death of Socrates, is also Plato's seventh and last dialogue to detail the philosopher's final days .In the dialogue, Socrates...

, Plato's teacher Socrates is made to say just before dying that his discovery of Anaxagoras' concept of a cosmic nous as the cause of the order of things, was an important turning point for him. But he also expressed disagreement with Anaxagoras' understanding of the implications of his own doctrine, because of Anaxagoras' materialist
Materialism
In philosophy, the theory of materialism holds that the only thing that exists is matter; that all things are composed of material and all phenomena are the result of material interactions. In other words, matter is the only substance...

 understanding of causation
Causality
Causality is the relationship between an event and a second event , where the second event is understood as a consequence of the first....

. Socrates said that Anaxagoras would "give voice and air and hearing and countless other things of the sort as causes for our talking with each other, and should fail to mention the real causes, which are, that the Athenians decided that it was best to condemn me". On the other hand Socrates seems to suggest that he also failed to develop a fully satisfactory teleological and dualistic understanding of a mind of nature, whose aims represent the good things which all parts of nature aim at.

Concerning the nous of individuals, the source of understanding, in opposition to Anaxagoras Plato is also widely understood to have accepted ideas from Parmenides
Parmenides
Parmenides of Elea was an ancient Greek philosopher born in Elea, a Greek city on the southern coast of Italy. He was the founder of the Eleatic school of philosophy. The single known work of Parmenides is a poem, On Nature, which has survived only in fragmentary form. In this poem, Parmenides...

 which affect his explanation of nous. Like Parmenides, Plato argued that relying on sense perception can never lead to true knowledge, only opinion. Instead, Plato's more philosophical characters argue that nous must somehow perceive truth directly in the ways gods and daimons perceive. What our mind sees directly in order to really understand things must not be the constantly changing material things, but unchanging entities that exist in a different way, the so called "forms
Theory of Forms
Plato's theory of Forms or theory of Ideas asserts that non-material abstract forms , and not the material world of change known to us through sensation, possess the highest and most fundamental kind of reality. When used in this sense, the word form is often capitalized...

" or "idea
Idea
In the most narrow sense, an idea is just whatever is before the mind when one thinks. Very often, ideas are construed as representational images; i.e. images of some object. In other contexts, ideas are taken to be concepts, although abstract concepts do not necessarily appear as images...

s". However he knew that contemporary philosophers often argued (as in modern science) that nous and perception are just two aspects of one physical activity, and that perception is the source of knowledge and understanding (not the other way around).

Just exactly how Plato believed that the nous of people lets them come to understand things in any way which improves upon sense perception is a subject of long running discussion and debate. On the one hand, in the Republic Plato's Socrates, in the so-called "metaphor of the sun", and "allegory of the cave
Allegory of the cave
The Allegory of the Cave—also known as the Analogy of the Cave, Plato's Cave, or the Parable of the Cave—is an allegory used by the Greek philosopher Plato in his work The Republic to illustrate "our nature in its education and want of education"...

" sections describe people as being able to see more clearly because of something from outside themselves, something like when sun shines, helping eyesight. This illumination of the intellect shines from the Form of the Good. On the other hand, in the Meno
Meno
Meno is a Socratic dialogue written by Plato. It attempts to determine the definition of virtue, or arete, meaning virtue in general, rather than particular virtues, such as justice or temperance. The first part of the work is written in the Socratic dialectical style and Meno is reduced to...

for example, Plato's Socrates explains the theory of anamnesis
Anamnesis (philosophy)
In philosophy, anamnesis is a concept in Plato's epistemological and psychological theory that he develops in his dialogues Meno and Phaedo, and alludes to it in his Phaedrus.-Meno:...

whereby people are born with ideas already in their soul, which they somehow remember from previous lives
Reincarnation
Reincarnation best describes the concept where the soul or spirit, after the death of the body, is believed to return to live in a new human body, or, in some traditions, either as a human being, animal or plant...

. Both theories were to be highly influential.

As in Xenophon, and apparently based upon Socrates, Plato frequently describes the soul in a political way, with ruling parts, and parts which are by nature meant to be ruled. Nous is associated with the rational (logistikon) part of the individual human soul, which by nature should rule. In his Republic
Republic (Plato)
The Republic is a Socratic dialogue written by Plato around 380 BC concerning the definition of justice and the order and character of the just city-state and the just man...

, in the so-called "analogy of the divided line
Analogy of the divided line
Plato, in his dialogue The Republic Book 6 , has Socrates explain through the literary device of a divided line his fundamental metaphysical ideas as four separate but logically connected models of the world. The four models are arranged into a first pair for the visible world, and a second pair...

", it has a special function within this rational part. Plato tended to treat nous as the only immortal part of the soul
Soul
A soul in certain spiritual, philosophical, and psychological traditions is the incorporeal essence of a person or living thing or object. Many philosophical and spiritual systems teach that humans have souls, and others teach that all living things and even inanimate objects have souls. The...

.

Concerning the cosmos, in the Timaeus
Timaeus (dialogue)
Timaeus is one of Plato's dialogues, mostly in the form of a long monologue given by the title character, written circa 360 BC. The work puts forward speculation on the nature of the physical world and human beings. It is followed by the dialogue Critias.Speakers of the dialogue are Socrates,...

, the title character also tells a likely story in which nous is responsible for the creative work of the demiurge
Demiurge
The demiurge is a concept from the Platonic, Neopythagorean, Middle Platonic, and Neoplatonic schools of philosophy for an artisan-like figure responsible for the fashioning and maintenance of the physical universe. The term was subsequently adopted by the Gnostics...

 or maker who brought rational order to our universe. This craftsman imitated what he perceived in the world of eternal Forms. In the Philebus
Philebus
The Philebus , composed between 360 and 347 BC, is among the last of the late Socratic dialogues of the ancient Greek philosopher Plato. Socrates is the primary speaker in Philebus, unlike in the other late dialogues...

Socrates argues that nous in individual humans must share in a cosmic nous, in the same way that human bodies are made up of small parts of the elements found in the rest of the universe. And this nous must be in the genos
Genos
Genos was the ancient Greek term for kind; race; family; birth; origin which identified themselves as a unit, referred to by a single name...

of being a cause of all particular things as particular things.

Aristotle


Like Plato, Aristotle saw the nous or intellect
Intellect
Intellect is a term used in studies of the human mind, and refers to the ability of the mind to come to correct conclusions about what is true or real, and about how to solve problems...

 of an individual as an intuitive understanding, distinguished from sense perception. Like Plato, Aristotle linked nous to logos (reason) as uniquely human, but he also distinguished nous from logos, thereby distinguishing the faculty for setting definitions from the faculty which uses them to reason with. In his Nicomachean Ethics
Nicomachean Ethics
The Nicomachean Ethics is the name normally given to Aristotle's best known work on ethics. The English version of the title derives from Greek Ἠθικὰ Νικομάχεια, transliterated Ethika Nikomacheia, which is sometimes also given in the genitive form as Ἠθικῶν Νικομαχείων, Ethikōn Nikomacheiōn...

, Book VI Aristotle divides the soul (psuchē) into two parts, one which has reason and one which does not, but then divides the part which has reason into the reasoning (logistikos) part itself which is lower, and the higher "knowing" (epistēmonikos) part which contemplates general principles (archai). Nous, he states, is the source of the first principles or sources (archai) of definitions, and it develops naturally as people get older. This he explains after first comparing the four other truth
Truth
Truth has a variety of meanings, such as the state of being in accord with fact or reality. It can also mean having fidelity to an original or to a standard or ideal. In a common usage, it also means constancy or sincerity in action or character...

 revealing capacities of soul: technical know how (technē
Techne
Techne, or techné, as distinguished from episteme, is etymologically derived from the Greek word τέχνη which is often translated as craftsmanship, craft, or art. It is the rational method involved in producing an object or accomplishing a goal or objective...

), logic
Logic
In philosophy, Logic is the formal systematic study of the principles of valid inference and correct reasoning. Logic is used in most intellectual activities, but is studied primarily in the disciplines of philosophy, mathematics, semantics, and computer science...

ally deduced
Deductive reasoning
Deductive reasoning, also called deductive logic, is reasoning which constructs or evaluates deductive arguments. Deductive arguments are attempts to show that a conclusion necessarily follows from a set of premises or hypothesis...

 knowledge
Knowledge
Knowledge is a familiarity with someone or something unknown, which can include information, facts, descriptions, or skills acquired through experience or education. It can refer to the theoretical or practical understanding of a subject...

 (epistēmē
Episteme
Episteme, as distinguished from techne, is etymologically derived from the Greek word ἐπιστήμη for knowledge or science, which comes from the verb ἐπίσταμαι, "to know".- The Concept of an "Episteme" in Michel Foucault :...

, sometimes translated as "scientific knowledge"), practical wisdom (phronēsis
Phronesis
Phronēsis is an Ancient Greek word for wisdom or intelligence which is a common topic of discussion in philosophy. In Aristotelian Ethics, for example in the Nicomachean Ethics it is distinguished from other words for wisdom as the virtue of practical thought, and is usually translated "practical...

), and lastly theoretical
Theory
The English word theory was derived from a technical term in Ancient Greek philosophy. The word theoria, , meant "a looking at, viewing, beholding", and referring to contemplation or speculation, as opposed to action...

 wisdom
Wisdom
Wisdom is a deep understanding and realization of people, things, events or situations, resulting in the ability to apply perceptions, judgements and actions in keeping with this understanding. It often requires control of one's emotional reactions so that universal principles, reason and...

 (sophia), which is defined by Aristotle as the combination of nous and epistēmē. All of these others apart from nous involve reason (logos).
Aristotle
Aristotle
Aristotle was a Greek philosopher and polymath, a student of Plato and teacher of Alexander the Great. His writings cover many subjects, including physics, metaphysics, poetry, theater, music, logic, rhetoric, linguistics, politics, government, ethics, biology, and zoology...

's philosophical works continue many of the same Socratic themes as his teacher Plato. Amongst the new proposals he made was a way of explaining causality, and nous is an important part of his explanation. As mentioned above, Plato criticized Anaxagoras' materialism, or understanding that the intellect of nature only set the cosmos in motion, but is no longer seen as the cause of physical events. Aristotle explained that the changes of things can be described in terms of four causes
Four causes
Four Causes refers to a principle in Aristotelian science that is used to understand change. Aristotle described four different types of causes, or ways in which an object could be explained: "we do not have knowledge of a thing until we have grasped its why, that is to say, its cause", He argued...

 at the same time. Two of these four causes are similar to the materialist understanding: each thing has a material which causes it to be how it is, and some other thing which set in motion or initiated some process of change. But at the same time according to Aristotle each thing is also caused by the natural forms they are tending to become, and the natural ends or aims, which somehow exist in nature as causes, even in cases where human plans and aims are not involved. These latter two causes, are concepts no longer used in modern science, encompassing the continuing effect of the ordering principle of nature itself. Aristotle's special description of causality is especially apparent in the natural development of living things. It leads to a method whereby Aristotle analyses causation and motion in terms of the potentialities and actualities
Potentiality and actuality
In philosophy, Potentiality and Actuality are principles of a dichotomy which Aristotle used throughout his philosophical works to analyze motion, causality, ethics, and physiology in his Physics, Metaphysics, Ethics and De Anima .The concept of potentiality, in this context, generally refers to...

 of all things, whereby all matter possesses various possibilities or potentialities of form and end, and these possibilities become more fully real as their potential forms become actual or active reality (something they will do on their own, by nature, unless stopped because of other natural things happening). For example a stone has in its nature the potentiality of falling to the earth and it will do so, and actualize this natural tendency, if nothing is in the way.

Aristotle analyzed thinking in the same way. For him, the possibility of understanding rests on the relationship of intellect
Intellect
Intellect is a term used in studies of the human mind, and refers to the ability of the mind to come to correct conclusions about what is true or real, and about how to solve problems...

 and sense
Sense
Senses are physiological capacities of organisms that provide inputs for perception. The senses and their operation, classification, and theory are overlapping topics studied by a variety of fields, most notably neuroscience, cognitive psychology , and philosophy of perception...

 perception
Perception
Perception is the process of attaining awareness or understanding of the environment by organizing and interpreting sensory information. All perception involves signals in the nervous system, which in turn result from physical stimulation of the sense organs...

. Aristotle's remarks on the concept of what came to be called the "active intellect
Active intellect
The active intellect is a concept in classical and medieval philosophy...

" and "passive intellect
Passive intellect
Passive intellect is a term used in philosophy to refer to the material aspect of the intellect , in accordance with the theory of hylomorphism.-Aristotle:In Aristotle's philosophy of mind, the passive intellect...

" (along with various other terms) are amongst "the most intensely studied sentences in the history of philosophy". The terms are derived from a single passage in Aristotle's
Aristotle
Aristotle was a Greek philosopher and polymath, a student of Plato and teacher of Alexander the Great. His writings cover many subjects, including physics, metaphysics, poetry, theater, music, logic, rhetoric, linguistics, politics, government, ethics, biology, and zoology...

 De Anima
On the Soul
On the Soul is a major treatise by Aristotle on the nature of living things. His discussion centres on the kinds of souls possessed by different kinds of living things, distinguished by their different operations...

, Book III. Following is the translation of one of those passages with some key Greek words shown in square brackets.
...since in nature
Nature (philosophy)
Nature is a concept with two major sets of inter-related meanings, referring on the one hand to the things which are natural, or subject to the normal working of "laws of nature", or on the other hand to the essential properties and causes of those things to be what they naturally are, or in other...

 one thing is the material [hulē
Matter
Matter is a general term for the substance of which all physical objects consist. Typically, matter includes atoms and other particles which have mass. A common way of defining matter is as anything that has mass and occupies volume...

] for each kind [genos
Genos
Genos was the ancient Greek term for kind; race; family; birth; origin which identified themselves as a unit, referred to by a single name...

] (this is what is in potency all the particular things of that kind) but it is something else that is the causal and productive thing by which all of them are formed, as is the case with an art in relation to its material, it is necessary in the soul [psuchē
Psyche (psychology)
The word psyche has a long history of use in psychology and philosophy, dating back to ancient times, and has been one of the fundamental concepts for understanding human nature from a scientific point of view. The English word soul is sometimes used synonymously, especially in older...

] too that these distinct aspects be present;

the one sort is intellect [nous] by becoming all things, the other sort by forming all things, in the way an active condition [hexis
Hexis
Hexis is a Greek word, important in the philosophy of Aristotle, and because of this it has become a traditional word of philosophy. It stems from a verb related to possession or "having", and Jacob Klein, for example, translates it as "possession". It is more typically translated in modern texts...

] like light
Light
Light or visible light is electromagnetic radiation that is visible to the human eye, and is responsible for the sense of sight. Visible light has wavelength in a range from about 380 nanometres to about 740 nm, with a frequency range of about 405 THz to 790 THz...

 too makes the colors that are in potency be at work as colors [to phōs poiei ta dunamei
Dunamis
In philosophy, Potentiality and Actuality are principles of a dichotomy which Aristotle used throughout his philosophical works to analyze motion, causality, ethics, and physiology in his Physics, Metaphysics, Ethics and De Anima .The concept of potentiality, in this context, generally refers to...

 onta chrōmata energeiai chrōmata
].

This sort of intellect [which is like light in the way it makes potential things work as what they are] is separate, as well as being without attributes and unmixed, since it is by its thinghood a being-at-work [energeia], for what acts is always distinguished in stature above what is acted upon, as a governing source is above the material it works on.

Knowledge
Knowledge
Knowledge is a familiarity with someone or something unknown, which can include information, facts, descriptions, or skills acquired through experience or education. It can refer to the theoretical or practical understanding of a subject...

 [epistēmē], in its being-at-work, is the same as the thing it knows, and while knowledge in potency comes first in time in any one knower, in the whole of things it does not take precedence even in time.

This does not mean that at one time it thinks but at another time it does not think, but when separated it is just exactly what it is, and this alone is deathless and everlasting (though we have no memory, because this sort of intellect is not acted upon, while the sort that is acted upon is destructible), and without this nothing thinks.


The passage tries to explain "how the human intellect passes from its original state, in which it does not think, to a subsequent state, in which it does" according to his distinction between potentiality and actuality. Aristotle says that the passive intellect receives the intelligible form
Intelligible form
An intelligible form in philosophy refers to a form that can be apprehended by the intellect. According to Ancient and Medieval philosophers, the intelligible forms are the things by which we understand.-Aristotle:...

s of things, but that the active intellect is required to make the potential knowledge into actual knowledge, in the same way that light makes potential colors into actual colors. As Davidson remarks:
Just what Aristotle meant by potential intellect and active intellect - terms not even explicit in the De anima and at best implied - and just how he understood the interaction between them remains moot. Students of the history of philosophy continue to debate Aristotle's intent, particularly the question whether he considered the active intellect to be an aspect of the human soul or an entity existing independently of man.


The passage is often read together with Metaphysics
Metaphysics (Aristotle)
Metaphysics is one of the principal works of Aristotle and the first major work of the branch of philosophy with the same name. The principal subject is "being qua being", or being understood as being. It examines what can be asserted about anything that exists just because of its existence and...

, Book XII, ch.7-10, where Aristotle makes nous as an actuality a central subject within a discussion of the cause of being and the cosmos. In that book, Aristotle equates active nous, when people think and their nous becomes what they think about, with the "unmoved mover
Unmoved mover
The unmoved mover is a philosophical concept described by Aristotle as a primary cause or "mover" of all the motion in the universe. As is implicit in the name, the "unmoved mover" is not moved by any prior action...

" of the universe, and God
God
God is the English name given to a singular being in theistic and deistic religions who is either the sole deity in monotheism, or a single deity in polytheism....

: "For the actuality of thought (nous) is life, and God is that actuality; and the essential actuality of God is life most good and eternal." Alexander of Aphrodisias, for example, equated this active intellect which is God with the one explained in De Anima, while Themistius thought they could not be simply equated. (See below.)

Like Plato before him, Aristotle believes Anaxagoras' cosmic nous implies and requires the cosmos to have intentions or ends: "Anaxagoras makes the Good a principle as causing motion; for Mind (nous) moves things, but moves them for some end, and therefore there must be some other Good—unless it is as we say; for on our view the art of medicine is in a sense health."

In the philosophy of Aristotle the soul (psyche
Psyche (psychology)
The word psyche has a long history of use in psychology and philosophy, dating back to ancient times, and has been one of the fundamental concepts for understanding human nature from a scientific point of view. The English word soul is sometimes used synonymously, especially in older...

) of a body is what makes it alive, and is its actualized form; thus, every living thing, including plant life, has a soul. The mind or intellect (nous) can be described variously as a power, faculty, part, or aspect of the human soul. It should be noted that for Aristotle soul and intellect are not the same. He did not rule out the possibility that intellect might survive without the rest of the soul, as in Plato, but plants have a 'nutritive' soul without a nous. In his Generation of Animals
Generation of Animals
The Generation of Animals is a text by Aristotle.-Arabic translation:...

Aristotle specifically says that while other parts of the soul come from the parents, physically, the nous, must come from outside, into the body, because it is divine or godly, and it has nothing in common with the energeia of the body. This was yet another passage which Alexander of Aphrodisias would link to those mentioned above from De Anima and the Metaphysics in order to understand Aristotle's intentions.

Post Aristotelian classical theories


Until the early modern era, much of the discussion which has survived today concerning nous or intellect, in Europe, Africa and the Middle East, concerned how to correctly interpret Aristotle and Plato. However, at least during the classical period, materialist philosophies, more similar to modern science, such as Epicureanism
Epicureanism
Epicureanism is a system of philosophy based upon the teachings of Epicurus, founded around 307 BC. Epicurus was an atomic materialist, following in the steps of Democritus. His materialism led him to a general attack on superstition and divine intervention. Following Aristippus—about whom...

, were still relatively common also. The Epicureans believed that the bodily senses themselves were not the cause of error, but the interpretations can be. The term prolepsis was used by Epicureans to describe the way the mind forms general concepts from sense perceptions.

To the Stoics, more like Heraclitus than Anaxagoras, order in the cosmos comes from an entity called logos
Logos
' is an important term in philosophy, psychology, rhetoric and religion. Originally a word meaning "a ground", "a plea", "an opinion", "an expectation", "word," "speech," "account," "reason," it became a technical term in philosophy, beginning with Heraclitus ' is an important term in...

, the cosmic
Cosmos
In the general sense, a cosmos is an orderly or harmonious system. It originates from the Greek term κόσμος , meaning "order" or "ornament" and is antithetical to the concept of chaos. Today, the word is generally used as a synonym of the word Universe . The word cosmos originates from the same root...

 reason
Reason
Reason is a term that refers to the capacity human beings have to make sense of things, to establish and verify facts, and to change or justify practices, institutions, and beliefs. It is closely associated with such characteristically human activities as philosophy, science, language, ...

. But as in Anaxagoras this cosmic reason, like human reason but higher, is connected to the reason of individual humans. The Stoics however, did not invoke incorporeal causation, but attempted to explain physics and human thinking in terms of matter and forces. As in Aristotelianism, they explained the interpretation of sense data requiring the mind to be stamped or formed with ideas. However, they did not propose any in-born or acquired equivalent of the "active intellect" in order to explain how people could know understand things. Nous for them is soul "somehow disposed" (pôs echon), the soul being somehow disposed pneuma
Pneuma
Pneuma is an ancient Greek word for "breath," and in a religious context for "spirit" or "soul." It has various technical meanings for medical writers and philosophers of classical antiquity, particularly in regard to physiology, and is also used in Greek translations of the Hebrew Bible and in...

, which is fire or air or a mixture. As in Plato, they treated nous as the ruling part of the soul.

Plutarch
Plutarch
Plutarch then named, on his becoming a Roman citizen, Lucius Mestrius Plutarchus , c. 46 – 120 AD, was a Greek historian, biographer, essayist, and Middle Platonist known primarily for his Parallel Lives and Moralia...

 criticized the Stoic idea of nous being corporeal, and agreed with Plato that the soul is more divine than the body while nous (mind) is more divine than the soul. The mix of soul and body produces pleasure
Pleasure
Pleasure describes the broad class of mental states that humans and other animals experience as positive, enjoyable, or worth seeking. It includes more specific mental states such as happiness, entertainment, enjoyment, ecstasy, and euphoria...

 and pain
Pain
Pain is an unpleasant sensation often caused by intense or damaging stimuli such as stubbing a toe, burning a finger, putting iodine on a cut, and bumping the "funny bone."...

; the conjunction of mind and soul produces reason
Reason
Reason is a term that refers to the capacity human beings have to make sense of things, to establish and verify facts, and to change or justify practices, institutions, and beliefs. It is closely associated with such characteristically human activities as philosophy, science, language, ...

 which is the cause or the source of virtue
Virtue
Virtue is moral excellence. A virtue is a positive trait or quality subjectively deemed to be morally excellent and thus is valued as a foundation of principle and good moral being....

 and vice
Vice
Vice is a practice or a behavior or habit considered immoral, depraved, or degrading in the associated society. In more minor usage, vice can refer to a fault, a defect, an infirmity, or merely a bad habit. Synonyms for vice include fault, depravity, sin, iniquity, wickedness, and corruption...

. (From: “On the Face in the Moon”)

Albinus
Albinus (philosopher)
Albinus was a Platonist philosopher, who lived at Smyrna, and was teacher of Galen. A short tract by him, entitled Introduction to Plato's dialogues, has come down to us. From the title of one of the extant manuscripts we learn that Albinus was a pupil of Gaius the Platonist...

 was one of the earliest authors to equate Aristotle's nous as prime mover
Primum movens
Primum movens , usually referred to as the Prime mover or first cause in English, is a term used in the philosophy of Aristotle, in the theological cosmological argument for the existence of God, and in cosmogony, the source of the cosmos or "all-being".-Aristotle's ontology:In book 12 of his...

 of the Universe, with Plato's Form of the Good.

Alexander of Aphrodisias



Alexander of Aphrodisias
Alexander of Aphrodisias
Alexander of Aphrodisias was a Peripatetic philosopher and the most celebrated of the Ancient Greek commentators on the writings of Aristotle. He was a native of Aphrodisias in Caria, and lived and taught in Athens at the beginning of the 3rd century, where he held a position as head of the...

 was a Peripatetic (Aristotelian) and his On the Soul (referred to as De anima in its traditional Latin title), explained that by his interpretation of Aristotle, potential intellect in man, that which has no nature but receives on from the active intellect, is material, and also called the "material intellect" (nous hulikos) and it is inseparable from the body, being "only a disposition" of it. He argued strongly against the doctrine of immortality. On the other hand, he identified the active intellect (nous poietikos), through whose agency the potential intellect in man becomes actual, not with anything from within people, but with the divine creator itself. In the early Renaissance his doctrine of the soul's mortality was adopted by Pietro Pomponazzi
Pietro Pomponazzi
Pietro Pomponazzi was an Italian philosopher. He is sometimes known by his Latin name, Petrus Pomponatius.-Biography:...

 against the Thomists and the Averroists. For him, the only possible human immortality is an immortality of a detached human thought, more specifically when the nous has as the object of its thought the active intellect itself, or another incorporeal intelligible form.

Alexander was also responsible for influencing the development of several more technical terms concerning the intellect, which became very influential amongst the great Islamic philosophers, Al-Farabi
Al-Farabi
' known in the West as Alpharabius , was a scientist and philosopher of the Islamic world...

, Avicenna
Avicenna
Abū ʿAlī al-Ḥusayn ibn ʿAbd Allāh ibn Sīnā , commonly known as Ibn Sīnā or by his Latinized name Avicenna, was a Persian polymath, who wrote almost 450 treatises on a wide range of subjects, of which around 240 have survived...

, and Averroes
Averroes
' , better known just as Ibn Rushd , and in European literature as Averroes , was a Muslim polymath; a master of Aristotelian philosophy, Islamic philosophy, Islamic theology, Maliki law and jurisprudence, logic, psychology, politics, Arabic music theory, and the sciences of medicine, astronomy,...

.
  • The intellect in habitu is a stage in which the human intellect has taken possession of a repertoire of thoughts, and so is potentially able to think those thoughts, but is not yet thinking these thoughts.
  • The intellect from outside, which became the "acquired intellect" in Islamic philosophy, describes the incorporeal active intellect which comes from outside man, and becomes an object thought, making the material intellect actual and active. This term may have come from a particularly expressive translation of Alexander into Arabic. Plotinus also used such a term. In any case, in Al-Farabi and Avicenna, the term took on a new meaning, distinguishing it from the active intellect in any simple sense - an ultimate stage of the human intellect where the a kind of close relationship (a "conjunction") is made between a person's active intellect and the transcendental nous itself.

Themistius



Themistius
Themistius
Themistius , named , was a statesman, rhetorician, and philosopher. He flourished in the reigns of Constantius II, Julian, Jovian, Valens, Gratian, and Theodosius I; and he enjoyed the favour of all those emperors, notwithstanding their many differences, and the fact that he himself was not a...

, another influential commentator on this matter, understood Aristotle differently, stating that the passive or material intellect does "not employ a bodily organ for its activity, is wholly unmixed with the body, impassive, and separate [from matter]". This means the human potential intellect, and not only the active intellect, is an incorporeal substance, or a disposition of incorporeal substance. For Themistius, the human soul becomes immortal "as soon as the active intellect intertwines with it at the outset of human thought".

This understanding of the intellect was also very influential for Al-Farabi
Al-Farabi
' known in the West as Alpharabius , was a scientist and philosopher of the Islamic world...

, Avicenna
Avicenna
Abū ʿAlī al-Ḥusayn ibn ʿAbd Allāh ibn Sīnā , commonly known as Ibn Sīnā or by his Latinized name Avicenna, was a Persian polymath, who wrote almost 450 treatises on a wide range of subjects, of which around 240 have survived...

, and Averroes
Averroes
' , better known just as Ibn Rushd , and in European literature as Averroes , was a Muslim polymath; a master of Aristotelian philosophy, Islamic philosophy, Islamic theology, Maliki law and jurisprudence, logic, psychology, politics, Arabic music theory, and the sciences of medicine, astronomy,...

, and "virtually all Islamic and Jewish philosophers". On the other hand concerning the active intellect, like Alexander and Plotinus, he saw this as a transcendent being existing above and outside man. Differently from Alexander, he did not equate this being with the first cause of the Universe itself, but something lower. However he equated it with Plato's Idea of the Good.

Plotinus and neoplatonism



Of the later Greek and Roman writers Plotinus
Plotinus
Plotinus was a major philosopher of the ancient world. In his system of theory there are the three principles: the One, the Intellect, and the Soul. His teacher was Ammonius Saccas and he is of the Platonic tradition...

, the intiator of neoplatonism
Neoplatonism
Neoplatonism , is the modern term for a school of religious and mystical philosophy that took shape in the 3rd century AD, based on the teachings of Plato and earlier Platonists, with its earliest contributor believed to be Plotinus, and his teacher Ammonius Saccas...

, is particularly significant. Like Alexander of Aphrodisias and Themistius, he saw himself as a commentator explaining the doctrines of Plato and Aristotle. But in his Enneads
Enneads
The Six Enneads, sometimes abbreviated to The Enneads or Enneads , is the collection of writings of Plotinus, edited and compiled by his student Porphyry . Plotinus was a student of Ammonius Saccas and they were founders of Neoplatonism...

he went further than those authors, often working from passages which had been presented more tentatively, possibly inspired partly by earlier authors such as the neopythagorean Numenius of Apamea
Numenius of Apamea
Numenius of Apamea was a Greek philosopher, who lived in Apamea in Syria and flourished during the latter half of the 2nd century AD. He was a Neopythagorean and forerunner of the Neoplatonists.- Philosophy :...

. Neoplatonism provided a major inspiration to discussion concerning the intellect in late classical and medieval philosophy, theology and cosmology.

In neoplatonism there exists several levels or hypostases of being, including the natural and visible world as a lower part.
  • The Monad
    Monism
    Monism is any philosophical view which holds that there is unity in a given field of inquiry. Accordingly, some philosophers may hold that the universe is one rather than dualistic or pluralistic...

     or "the One" sometimes also described as "the Good", based on the concept as it is found in Plato. This is the dunamis
    Dunamis
    In philosophy, Potentiality and Actuality are principles of a dichotomy which Aristotle used throughout his philosophical works to analyze motion, causality, ethics, and physiology in his Physics, Metaphysics, Ethics and De Anima .The concept of potentiality, in this context, generally refers to...

    or possibility of existence. It causes the other levels by emanation.
  • The Nous (usually translated as "Intellect", or "Intelligence" in this context, or sometimes "mind" or "reason") is described as God, or more precisely an image of God, often referred to as the Demiurge
    Demiurge
    The demiurge is a concept from the Platonic, Neopythagorean, Middle Platonic, and Neoplatonic schools of philosophy for an artisan-like figure responsible for the fashioning and maintenance of the physical universe. The term was subsequently adopted by the Gnostics...

    . It thinks its own contents, which are thoughts, equated to the Platonic ideas or forms
    Theory of Forms
    Plato's theory of Forms or theory of Ideas asserts that non-material abstract forms , and not the material world of change known to us through sensation, possess the highest and most fundamental kind of reality. When used in this sense, the word form is often capitalized...

     (eide). The thinking of this Intellect is the highest activity of life. The actualization (energeia) of this thinking is the being of the forms. This Intellect is the first principle or foundation of existence. The One is prior to it, but not in the sense that a normal cause is prior to an effect, but instead Intellect is called an emanation of the One. The One is the possibility of this foundation of existence.
  • Soul
    Soul
    A soul in certain spiritual, philosophical, and psychological traditions is the incorporeal essence of a person or living thing or object. Many philosophical and spiritual systems teach that humans have souls, and others teach that all living things and even inanimate objects have souls. The...

     (psuchē). The soul is also an energeia: it acts upon or actualizes its own thoughts and creates "a separate, material cosmos that is the living image of the spiritual or noetic Cosmos
    Cosmos
    In the general sense, a cosmos is an orderly or harmonious system. It originates from the Greek term κόσμος , meaning "order" or "ornament" and is antithetical to the concept of chaos. Today, the word is generally used as a synonym of the word Universe . The word cosmos originates from the same root...

     contained as a unified thought within the Intelligence". So it is the soul which perceives things in nature physically, which it understands to be reality. Soul in Plotinus plays a role similar to the potential intellect in Aristotelian terminology.
  • Lowest is matter.

This was based largely upon Plotinus' reading of Plato, but also incorporated many Aristotelian concepts, including the Unmoved Mover
Unmoved mover
The unmoved mover is a philosophical concept described by Aristotle as a primary cause or "mover" of all the motion in the universe. As is implicit in the name, the "unmoved mover" is not moved by any prior action...

 as energeia. They also incorporated a theory of anamnesis, or knowledge coming from the past lives of our immortal souls, like that found in some of Plato's dialogues.

Later Platonists distinguished a hierarchy of three separate manifestations of nous, like Numenius of Apamea
Numenius of Apamea
Numenius of Apamea was a Greek philosopher, who lived in Apamea in Syria and flourished during the latter half of the 2nd century AD. He was a Neopythagorean and forerunner of the Neoplatonists.- Philosophy :...

 had. Notable later neoplatonists include Porphyry
Porphyry (philosopher)
Porphyry of Tyre , Porphyrios, AD 234–c. 305) was a Neoplatonic philosopher who was born in Tyre. He edited and published the Enneads, the only collection of the work of his teacher Plotinus. He also wrote many works himself on a wide variety of topics...

 and Proclus
Proclus
Proclus Lycaeus , called "The Successor" or "Diadochos" , was a Greek Neoplatonist philosopher, one of the last major Classical philosophers . He set forth one of the most elaborate and fully developed systems of Neoplatonism...

.

Gnosticism


Gnosticism was a late classical
Late Antiquity
Late Antiquity is a periodization used by historians to describe the time of transition from Classical Antiquity to the Middle Ages, in both mainland Europe and the Mediterranean world. Precise boundaries for the period are a matter of debate, but noted historian of the period Peter Brown proposed...

 movement which incorporated ideas inspired by neoplatonism and neopythagoreanism, but which was more syncretic
Syncretism
Syncretism is the combining of different beliefs, often while melding practices of various schools of thought. The term means "combining", but see below for the origin of the word...

 religious movement than an accepted philosophical movement.

Valentinus



In the Valentinian
Valentinus (Gnostic)
Valentinus was the best known and for a time most successful early Christian gnostic theologian. He founded his school in Rome...

 system, Nous is the first male Aeon
Aeon (Gnosticism)
In many Gnostic systems, the various emanations of God, who is also known by such names as the One, the Monad, Aion teleos , Bythos , Proarkhe , the Arkhe , are called Aeons...

. Together with his conjugate female Aeon, Aletheia (truth), he emanates from the Propator Bythos and his coeternal Ennoia or Sige; and these four form the primordial Tetrad. Like the other male Aeons he is sometimes regarded as androgynous, including in himself the female Aeon who is paired with him. He is the Only Begotten; and is styled the Father, the Beginning of all, inasmuch as from him are derived immediately or mediately the remaining Aeons who complete the Ogdoad
Ogdoad
In Egyptian mythology, the Ogdoad were eight deities worshipped in Hermopolis during what is called the Old Kingdom, the third through sixth dynasties, dated between 2686 to 2134 BC...

(eight), thence the Decad
Decad
Pythagorus regarded the number 10, or "decad" as being a perfect number, which was often represented by the tetractys, which embraced the whole nature of number....

(ten), and thence the Dodecad (twenty); in all thirty, Aeons constituting the Pleroma. He alone is capable of knowing the Propator; but when he desired to impart like knowledge to the other Aeons, was withheld from so doing by Sige. When Sophia (wisdom), youngest Aeon of the thirty, was brought into peril by her yearning after this knowledge, Nous was foremost of the Aeons in interceding for her. From him, or through him from the Propator, Horos was sent to restore her. After her restoration, Nous, according to the providence of the Propator, produced another pair, Christ
Christ
Christ is the English term for the Greek meaning "the anointed one". It is a translation of the Hebrew , usually transliterated into English as Messiah or Mashiach...

 and the Holy Spirit
Holy Spirit
Holy Spirit is a term introduced in English translations of the Hebrew Bible, but understood differently in the main Abrahamic religions.While the general concept of a "Spirit" that permeates the cosmos has been used in various religions Holy Spirit is a term introduced in English translations of...

, "in order to give fixity and steadfastness (eis pēxin kai stērigmon) to the Pleroma." For this Christ teaches the Aeons to be content to know that the Propator is in himself incomprehensible, and can be perceived only through the Only Begotten (Nous).

Basilides



A similar conception of Nous appears in the later teaching of the Basilidean School
Basilideans
The Basilidians or Basilideans were a Gnostic sect founded by Basilides of Alexandria in the 2nd century. Basilides claimed to have been taught his doctrines by Glaucus, a disciple of St...

, according to which he is the first begotten of the Unbegotten Father, and himself the parent of Logos
Logos
' is an important term in philosophy, psychology, rhetoric and religion. Originally a word meaning "a ground", "a plea", "an opinion", "an expectation", "word," "speech," "account," "reason," it became a technical term in philosophy, beginning with Heraclitus ' is an important term in...

, from whom emanate successively Phronesis
Phronesis
Phronēsis is an Ancient Greek word for wisdom or intelligence which is a common topic of discussion in philosophy. In Aristotelian Ethics, for example in the Nicomachean Ethics it is distinguished from other words for wisdom as the virtue of practical thought, and is usually translated "practical...

, Sophia, and Dunamis
Dunamis
In philosophy, Potentiality and Actuality are principles of a dichotomy which Aristotle used throughout his philosophical works to analyze motion, causality, ethics, and physiology in his Physics, Metaphysics, Ethics and De Anima .The concept of potentiality, in this context, generally refers to...

. But in this teaching Nous is identified with Christ, is named Jesus
Jesus
Jesus of Nazareth , commonly referred to as Jesus Christ or simply as Jesus or Christ, is the central figure of Christianity...

, is sent to save those that believe, and returns to Him who sent him, after a passion which is apparent only,—Simon the Cyrenian
Simon of Cyrene
Simon of Cyrene was the man compelled by the Romans to carry the cross of Jesus as Jesus was taken to his crucifixion, according to all three Synoptic Gospels...

 being substituted for him on the cross. It is probable, however, that Nous had a place in the original system of Basilides himself; for his Ogdoad, "the great Archon
Archon
Archon is a Greek word that means "ruler" or "lord", frequently used as the title of a specific public office. It is the masculine present participle of the verb stem ἀρχ-, meaning "to rule", derived from the same root as monarch, hierarchy, and anarchy.- Ancient Greece :In ancient Greece the...

 of the universe, the ineffable" is apparently made up of the five members named by Irenaeus
Irenaeus
Saint Irenaeus , was Bishop of Lugdunum in Gaul, then a part of the Roman Empire . He was an early church father and apologist, and his writings were formative in the early development of Christian theology...

 (as above), together with two whom we find in Clement
Clement of Alexandria
Titus Flavius Clemens , known as Clement of Alexandria , was a Christian theologian and the head of the noted Catechetical School of Alexandria. Clement is best remembered as the teacher of Origen...

, Dikaiosyne and Eirene,—added to the originating Father.

Simon Magus



The antecedent of these systems is that of Simon Magus
Simon Magus
Simon the Sorcerer or Simon the Magician, in Latin Simon Magus, was a Samaritan magus or religious figure and a convert to Christianity, baptised by Philip the Apostle, whose later confrontation with Peter is recorded in . The sin of simony, or paying for position and influence in the church, is...

, of whose six "roots" emanating from the Unbegotten Fire, Nous is first. The correspondence of these "roots" with the first six Aeons which Valentinus derives from Bythos, is noted by Hippolytus. Simon says in his Apophasis Megalē,

To Nous and Epinoia correspond Heaven and Earth, in the list given by Simon of the six material counterparts of his six emanations. The identity of this list with the six material objects alleged by Herodotus
Herodotus
Herodotus was an ancient Greek historian who was born in Halicarnassus, Caria and lived in the 5th century BC . He has been called the "Father of History", and was the first historian known to collect his materials systematically, test their accuracy to a certain extent and arrange them in a...

 to be worshipped by the Persians, together with the supreme place given by Simon to Fire as the primordial power, leads us to look to Persia for the origin of these systems in one aspect. In another, they connect themselves with the teaching of Pythagoras
Pythagoras
Pythagoras of Samos was an Ionian Greek philosopher, mathematician, and founder of the religious movement called Pythagoreanism. Most of the information about Pythagoras was written down centuries after he lived, so very little reliable information is known about him...

 and of Plato.

Gospel of Mary



According to the Gospel of Mary
Gospel of Mary
The Gospel of Mary is an apocryphal book discovered in 1896 in a 5th-century papyrus codex. The codex Papyrus Berolinensis 8502 was purchased in Cairo by German scholar Karl Reinhardt....

, Jesus himself articulates the essence of Nous:

Medieval Islamic, Jewish, and Christian Averroist philosophy



During the middle ages
Middle Ages
The Middle Ages is a periodization of European history from the 5th century to the 15th century. The Middle Ages follows the fall of the Western Roman Empire in 476 and precedes the Early Modern Era. It is the middle period of a three-period division of Western history: Classic, Medieval and Modern...

, philosophy itself was in many places seen as opposed to the prevailing monotheistic religions, Islam
Islam
Islam . The most common are and .   : Arabic pronunciation varies regionally. The first vowel ranges from ~~. The second vowel ranges from ~~~...

, Christianity
Christianity
Christianity is a monotheistic religion based on the life and teachings of Jesus as presented in canonical gospels and other New Testament writings...

 and Judaism
Judaism
Judaism ) is the "religion, philosophy, and way of life" of the Jewish people...

. The strongest philosophical tradition for some centuries was amongst Islamic philosophers, who later came to strongly influence the late medieval philosophers of western Christendom, and the Jewish diaspora
Jewish diaspora
The Jewish diaspora is the English term used to describe the Galut גלות , or 'exile', of the Jews from the region of the Kingdom of Judah and Roman Iudaea and later emigration from wider Eretz Israel....

 in the Mediterranean area. While there were earlier Muslim philosophers such as Al Kindi, chronologically the three most influential concerning the intellect were Al Farabi, Avicenna
Avicenna
Abū ʿAlī al-Ḥusayn ibn ʿAbd Allāh ibn Sīnā , commonly known as Ibn Sīnā or by his Latinized name Avicenna, was a Persian polymath, who wrote almost 450 treatises on a wide range of subjects, of which around 240 have survived...

, and finally Averroes
Averroes
' , better known just as Ibn Rushd , and in European literature as Averroes , was a Muslim polymath; a master of Aristotelian philosophy, Islamic philosophy, Islamic theology, Maliki law and jurisprudence, logic, psychology, politics, Arabic music theory, and the sciences of medicine, astronomy,...

, a westerner who lived in Spain and was highly influential in the late middle ages amongst Jewish and Christian philosophers.

Al Farabi



The exact precedents of Al Farabi's influential philosophical scheme, in which nous (Arabic 'aql
'Aql
‘Aql , is an Arabic language term used in Islamic theology or philosophy to the intellect the rational faculty of the soul or mind. It is the normal translation of the Greek term nous...

) plays an important role, are no longer perfectly clear because of the great loss of texts in the middle ages which he would have had access to. He was apparently innovative in at least some points. He was clearly influenced by the same late classical world as neoplatonism, neopythagoreanism, but exactly how is less clear. Plotinus, Themistius and Alexander of Aphrodisias are generally accepted to have been influences. However while these three all placed the active intellect "at or near the top of the hierarchy of being", Al Farabi was clear in making it the lowest ranking in a series of distinct transcendental intelligences. He is the first known person to have done this in a clear way. He was also the first philosopher known to have assumed the existence of a causal hierarchy of celestial spheres
Celestial spheres
The celestial spheres, or celestial orbs, were the fundamental entities of the cosmological models developed by Plato, Eudoxus, Aristotle, Ptolemy, Copernicus and others...

, and the incorporeal intelligences parallel to those spheres. Al Farabi also fitted an explanation of prophecy into this scheme, in two levels. According to Davidson (p. 59):
The lower of the two levels, labeled specifically as "prophecy" (nubuwwa), is enjoyed by men who have not yet perfected their intellect, whereas the higher, which Alfarabi sometimes specifically names "revelation" (w-ḥ-y), comes exclusively to those who stand at the stage of acquired intellect.

This happens in the imagination (Arabic mutakhayyila; Greek phantasia), a faculty of the mind already described by Aristotle, which Al Farabi described as serving the rational part of the soul (Arabic aql; Greek nous). This faculty of imagination stores sense perceptions (maḥsūsāt), disassembles or recombines them, creates figurative or symbolic images (muḥākāt) of them which then appear in dreams, visualizes present and predicted events in a way different from conscious deliberation (rawiyya). This is under the influence, according to Al Farabi, of the active intellect. Theoretical truth can only be received by this faculty in a figurative or symbolic form, because the imagination is a physical capability and can not receive theoretical information in a proper abstract form. This rarely comes in a waking state, but more often in dreams. The lower type of philosophy is the best possible for the imaginative faculty, but the higher type of prophecy requires not only a receptive imagination, but also the condition of an "acquired intellect", where the human nous is in "conjunction" with the active intellect in the sense of God. Such a prophet is also a philosopher. When a philosopher-prophet has the necessary leadership qualities, he becomes philosopher-king.

Avicenna



In terms of cosmology, according to Davidson (p. 82) "Avicenna's universe has a structure virtually identical with the structure of Alfarabi's" but there are differences in details. As in Al Farabi, there are several levels of intellect, intelligence or nous, each of the higher ones being associated with a celestial sphere. Avicenna however details three different types of effect which each of these higher intellects has, each "thinks" both the necessary existence and the possible being of the intelligence one level higher. And each "emanates" downwards the body and soul of its own celestial sphere, and also the intellect at the next lowest level. The active intellect, as in Alfarabi, is the last in the chain. Avicenna sees active intellect as the cause not only of intelligible thought and the forms in the "sublunar" world we people live, but also the matter. (In other words, three effects.)

Concerning the workings of the human soul, Avicenna, like Al Farabi, sees the "material intellect" or potential intellect as something that is not material. He believed the soul was incorporeal, and the potential intellect was a disposition of it which was in the soul from birth. As in Al Farabi there are two further stages of potential for thinking, which are not yet actual thinking, first the mind acquires the most basic intelligible thoughts which we can not think in any other way, such as "the whole is greater than the part", then comes a second level of derivative intelligible thoughts which could be thought. Concerning the actualization of thought, Avicenna applies the term "to two different things, to actual human thought, irrespective of of the intellectual progress a man has made, and to actual thought when human intellectual development is complete", as in Al Farabi.

When reasoning in the sense of deriving conclusions from syllogisms, Avicenna says people are using a physical "cogitative" faculty (mufakkira, fikra) of the soul, which can err. The human cogitative faculty is the same as the "compositive imaginative faculty (mutakhayyila) in reference to the animal soul". But some people can use "insight" to avoid this step and derive conclusions directly by conjoining with the active intellect.

Once a thought has been learned in a soul, the physical faculties of sense perception and imagination become unnecessary, and as a person acquires more thoughts, their soul becomes less connected to their body. For Avicenna, differently to the normal Aristotelian position, all of the soul is by nature immortal. But the level of intellectual development does affect the type of afterlife that the soul can have. Only a soul which has reached the highest type of conjunction with the active intellect can form a perfect conjunction with it after the death of the body, and this is a supreme eudaimonia
Eudaimonia
Eudaimonia or eudaemonia , sometimes Anglicized as eudemonia , is a Greek word commonly translated as happiness or welfare; however, "human flourishing" has been proposed as a more accurate translation...

. Lesser intellectual achievement means a less happy or even painful afterlife.

Concerning prophecy, Avicenna identifies a broader range of possibilities which fit into this model, which is still similar to that of Al Farabi.

Averroes



Averroes came to be regarded even in Europe as "the Commentator" to "the Philosopher", Aristotle, and his study of the questions surrounding the nous were very influential amongst Jewish and Christian philosophers, with some aspects being quite controversial. According to Herbert Davidson, Averroes' doctrine concerning nous can be divided into two periods. In the first, neoplatonic emanationism, not found in the original works of Aristotle, was combined with a naturalistic explanation of the human material intellect. "It also insists on the material intellect's having an active intellect as a direct object of thought and conjoining with the active intellect, notions never expressed in the Aristotelian canon." It was this presentation which Jewish philosophers such as Moses Narboni and Gersonides
Gersonides
Levi ben Gershon, better known by his Latinised name as Gersonides or the abbreviation of first letters as RaLBaG , philosopher, Talmudist, mathematician, astronomer/astrologer. He was born at Bagnols in Languedoc, France...

 understood to be Averroes'. In the later model of the universe, which was transmitted to Christian philosophers, Averroes "dismisses emanationism and explains the generation of living beings in the sublunar world naturalistically, all in the name of a more genuine Aristotelianism. Yet it abandons the earlier naturalistic conception of the human material intellect and transforms the material intellect into something wholly un-Aristotelian, a single transcendent entity serving all mankind. It nominally salvages human conjunction with the active intellect, but in words that have little content."

This position, that humankind shares one active intellect, was taken up by Parisian philosophers such as Siger of Brabant
Siger of Brabant
Siger of Brabant was a 13th century philosopher from the southern Low Countries who was an important proponent of Averroism...

, but also widely rejected by philosophers such as Albertus Magnus
Albertus Magnus
Albertus Magnus, O.P. , also known as Albert the Great and Albert of Cologne, is a Catholic saint. He was a German Dominican friar and a bishop, who achieved fame for his comprehensive knowledge of and advocacy for the peaceful coexistence of science and religion. Those such as James A. Weisheipl...

, Thomas Aquinas
Thomas Aquinas
Thomas Aquinas, O.P. , also Thomas of Aquin or Aquino, was an Italian Dominican priest of the Catholic Church, and an immensely influential philosopher and theologian in the tradition of scholasticism, known as Doctor Angelicus, Doctor Communis, or Doctor Universalis...

, Ramon Lull, and Duns Scotus
Duns Scotus
Blessed John Duns Scotus, O.F.M. was one of the more important theologians and philosophers of the High Middle Ages. He was nicknamed Doctor Subtilis for his penetrating and subtle manner of thought....

. Despite being widely considered heretical, the position was later defended by many more European philosophers including John of Jandun
John of Jandun
John of Jandun was an Averroist philosopher, theologian, and political writer. He was born at Jandun in the Ardennes, in what is now France...

, who was the primary link bringing this doctrine from Paris to Bologna. After him this position continued to be defended and also rejected by various writers in northern Italy. In the 16th century it finally became a less common position after the renewal of an "Alexandrian" position based on that of Alexander of Aphrodisias, associated with Pietro Pomponazzi
Pietro Pomponazzi
Pietro Pomponazzi was an Italian philosopher. He is sometimes known by his Latin name, Petrus Pomponatius.-Biography:...

.

Christianity


The Christian New Testament
New Testament
The New Testament is the second major division of the Christian biblical canon, the first such division being the much longer Old Testament....

 makes mention of the nous or noos in , ; , ; , ; ; and . In the writings of the Christian fathers
Church Fathers
The Church Fathers, Early Church Fathers, Christian Fathers, or Fathers of the Church were early and influential theologians, eminent Christian teachers and great bishops. Their scholarly works were used as a precedent for centuries to come...

 a sound or pure
nous is considered essential to the cultivation of wisdom
Wisdom
Wisdom is a deep understanding and realization of people, things, events or situations, resulting in the ability to apply perceptions, judgements and actions in keeping with this understanding. It often requires control of one's emotional reactions so that universal principles, reason and...

.

Philosophers influencing western Christianity


While philosophical works were not commonly read or taught in the early middle ages in most of Europe, the works of authors like Boethius and Augustine of Hippo
Augustine of Hippo
Augustine of Hippo , also known as Augustine, St. Augustine, St. Austin, St. Augoustinos, Blessed Augustine, or St. Augustine the Blessed, was Bishop of Hippo Regius . He was a Latin-speaking philosopher and theologian who lived in the Roman Africa Province...

 formed an important exception. Both were influenced by neoplatonism, and were amongst the older works that were still known in the time of the Carolingian Renaissance
Carolingian Renaissance
In the history of ideas the Carolingian Renaissance stands out as a period of intellectual and cultural revival in Europe occurring from the late eighth century, in the generation of Alcuin, to the 9th century, and the generation of Heiric of Auxerre, with the peak of the activities coordinated...

, and the beginnings of Scholasticism
Scholasticism
Scholasticism is a method of critical thought which dominated teaching by the academics of medieval universities in Europe from about 1100–1500, and a program of employing that method in articulating and defending orthodoxy in an increasingly pluralistic context...

.

In his early years he was heavily influenced by Manichaeism
Manichaeism
Manichaeism in Modern Persian Āyin e Māni; ) was one of the major Iranian Gnostic religions, originating in Sassanid Persia.Although most of the original writings of the founding prophet Mani have been lost, numerous translations and fragmentary texts have survived...

 and afterward by the Neo-Platonism of Plotinus
Plotinus
Plotinus was a major philosopher of the ancient world. In his system of theory there are the three principles: the One, the Intellect, and the Soul. His teacher was Ammonius Saccas and he is of the Platonic tradition...

. After his conversion to Christianity and baptism (387
387
Year 387 was a common year starting on Friday of the Julian calendar. At the time, it was known as the Year of the Consulship of Augustus and Eutropius...

), Augustine developed his own approach to philosophy and theology, accommodating a variety of methods and different perspectives.

Augustine used neoplatonism
Neoplatonism
Neoplatonism , is the modern term for a school of religious and mystical philosophy that took shape in the 3rd century AD, based on the teachings of Plato and earlier Platonists, with its earliest contributor believed to be Plotinus, and his teacher Ammonius Saccas...

 selectively. He used both the neoplatonic Nous, and the Platonic Form of the Good (or "The Idea of the Good") as equivalent terms for the Christian God, or at least for one particular aspect of God. For example, God, nous, can act directly upon matter, and not only through souls, and concerning the souls through which it works upon the world experienced by humanity, some are treated as angels.

Scholasticism becomes more clearly defined much later, as the peculiar native type of philosophy in medieval catholic Europe. In this period, Aristotle became "the Philosopher", and scholastic philosophers, like their Jewish and Muslim contemporaries, studied the concept of the intellectus on the basis not only of Aristotle, but also late classical interpreters like Augustine and Boethius. A European tradition of new and direct interpretations of Aristotle developed which was eventually strong enough to argue with partial success against some of the interpretations of Aristotle from the islamic world, most notably Averroes' doctrine of their being one "active intellect" for all humanity. Notable "Catholic
Catholic
The word catholic comes from the Greek phrase , meaning "on the whole," "according to the whole" or "in general", and is a combination of the Greek words meaning "about" and meaning "whole"...

" (as opposed to Averroist) Aristotelians included Albertus Magnus
Albertus Magnus
Albertus Magnus, O.P. , also known as Albert the Great and Albert of Cologne, is a Catholic saint. He was a German Dominican friar and a bishop, who achieved fame for his comprehensive knowledge of and advocacy for the peaceful coexistence of science and religion. Those such as James A. Weisheipl...

 and Thomas Aquinas
Thomas Aquinas
Thomas Aquinas, O.P. , also Thomas of Aquin or Aquino, was an Italian Dominican priest of the Catholic Church, and an immensely influential philosopher and theologian in the tradition of scholasticism, known as Doctor Angelicus, Doctor Communis, or Doctor Universalis...

, the founder Thomism
Thomism
Thomism is the philosophical school that arose as a legacy of the work and thought of St. Thomas Aquinas, philosopher, theologian, and Doctor of the Church. In philosophy, his commentaries on Aristotle are his most lasting contribution...

, which exists to this day in various forms. Concerning the nous, Thomism agrees with those Aristotelians who insist that the intellect is immaterial and separate from any bodily organs, but as per Christian doctrine, the whole of the human soul is immortal, not only the intellect.

Eastern Orthodox


The human
nous in Eastern Orthodox Christianity is the "eye of the heart or soul" or the "mind of the heart". The soul of man, is created by God in His image, man's soul is intelligent and noetic. St Thalassios wrote that God created beings "with a capacity to receive the Spirit and to attain knowledge of Himself; He has brought into existence the senses and sensory perception to serve such beings". Eastern Orthodox Christians hold that God did this by creating mankind with intelligence and noetic faculties.

Human reasoning is not enough: there will always remain an "irrational residue" which escapes analysis and which can not be expressed in concepts: it is this unknowable depth of things, that which constitutes their true, indefinable essence that also reflects the origin of things in God. In Eastern Christianity it is by faith or intuitive truth that this component of an objects existence is grasped. Though God through his energies draws us to him, his essence remains inaccessible. The operation of faith being the means of free will
Free will
"To make my own decisions whether I am successful or not due to uncontrollable forces" -Troy MorrisonA pragmatic definition of free willFree will is the ability of agents to make choices free from certain kinds of constraints. The existence of free will and its exact nature and definition have long...

 by which mankind faces the future or unknown, these noetic operations contained in the concept of insight
Insight
Insight is the understanding of a specific cause and effect in a specific context. Insight can be used with several related meanings:*a piece of information...

 or noesis. Faith (pistis) is therefore sometimes used interchangeably with noesis in Eastern Christianity
Eastern Christianity
Eastern Christianity comprises the Christian traditions and churches that developed in the Balkans, Eastern Europe, Asia Minor, the Middle East, Northeastern Africa, India and parts of the Far East over several centuries of religious antiquity. The term is generally used in Western Christianity to...

.

Angels have intelligence and
nous, whereas men have reason
Reason
Reason is a term that refers to the capacity human beings have to make sense of things, to establish and verify facts, and to change or justify practices, institutions, and beliefs. It is closely associated with such characteristically human activities as philosophy, science, language, ...

 both
logos and dianoia
Dianoia
Dianoia is a term used by Plato for a type of thinking, specifically about mathematical and technical subjects. It is the capacity for, process of, or result of discursive thinking, in contrast with the immediate apprehension that is characteristic of noesis...

, nous and sensory perception. This follows the idea that man is a microcosm
Macrocosm and microcosm
Macrocosm and microcosm is an ancient Greek Neo-Platonic schema of seeing the same patterns reproduced in all levels of the cosmos, from the largest scale all the way down to the smallest scale...

 and an expression of the whole creation or macrocosmos. The human
nous was darkened after the Fall of Man (which was the result of the rebellion of reason against the nous), but after the purification (healing or correction) of the nous (achieved through ascetic practices like hesychasm
Hesychasm
Hesychasm is an eremitic tradition of prayer in the Eastern Orthodox Church, and some of the Eastern Catholic Churches, such as the Byzantine Rite, practised by the Hesychast Hesychasm is an eremitic tradition of prayer in the Eastern Orthodox Church, and some of the Eastern Catholic Churches,...

), the human
nous (the "eye of the heart") will see God's uncreated Light
Theoria
For other uses of the term "contemplation", see Contemplation Theoria is Greek for contemplation. It corresponds to the Latin word contemplatio, "looking at", "gazing at", "being aware of".- Introduction :...

 (and feel God's uncreated love and beauty, at which point the nous will start the unceasing prayer of the heart) and become illuminated, allowing the person to become an orthodox theologian.

In this belief, the soul is created in the image of God. Since God is Trinitarian, Mankind is
Nous, reason
Reason
Reason is a term that refers to the capacity human beings have to make sense of things, to establish and verify facts, and to change or justify practices, institutions, and beliefs. It is closely associated with such characteristically human activities as philosophy, science, language, ...

 both
logos and dianoia and Spirit. The same is held true of the soul (or heart): it has nous, word and spirit. To understand this better first an understanding of St Gregory Palamas
Gregory Palamas
Gregory Palamas was a monk of Mount Athos in Greece and later the Archbishop of Thessaloniki known as a preeminent theologian of Hesychasm. The teachings embodied in his writings defending Hesychasm against the attack of Barlaam are sometimes referred to as Palamism, his followers as Palamites...

's teaching that man is a representation of the trinitarian mystery should be addressed. This holds that God is not meant in the sense that the Trinity
Trinity
The Christian doctrine of the Trinity defines God as three divine persons : the Father, the Son , and the Holy Spirit. The three persons are distinct yet coexist in unity, and are co-equal, co-eternal and consubstantial . Put another way, the three persons of the Trinity are of one being...

 should be understood anthropomorphically
Anthropomorphism
Anthropomorphism is any attribution of human characteristics to animals, non-living things, phenomena, material states, objects or abstract concepts, such as organizations, governments, spirits or deities. The term was coined in the mid 1700s...

, but man is to be understood in a triune way. Or, that the Trinitarian God is not to be interpreted from the point of view of individual man, but man is interpreted on the basis of the Trinitarian God. And this interpretation is revelatory not merely psychological and human. This means that it is only when a person is within the revelation, as all the saints lived, that he can grasp this understanding completely (see theoria
Theoria
For other uses of the term "contemplation", see Contemplation Theoria is Greek for contemplation. It corresponds to the Latin word contemplatio, "looking at", "gazing at", "being aware of".- Introduction :...

). The second presupposition is that mankind has and is composed of nous, word and spirit like the trinitarian mode of being. Man's nous, word and spirit are not hypostases or individual existences or realities, but activities or energies of the soul--whereas in the case with God or the Persons of the Holy Trinity, each are indeed hypostases. So these three components of each individual man are 'inseparable from one another' but they do not have a personal character" when in speaking of the being or ontology
Ontology
Ontology is the philosophical study of the nature of being, existence or reality as such, as well as the basic categories of being and their relations...

 that is mankind. The nous as the eye of the soul, which some Fathers also call the heart, is the center of man and is where true (spiritual) knowledge is validated. This is seen as true knowledge which is "implanted in the nous as always co-existing with it".

Early modern philosophy


The so called "early modern" philosophers
Early modern philosophy
Early modern philosophy is a period in the history of philosophy at the beginning or overlapping with the period known as modern philosophy. The early modern period in history is roughly 1500-1800, but the label "early modern philosophy" is sometimes used to refer to a more specific period of...

 of western Europe in the 17th and 18th centuries established arguments which led to the establishment of modern science as a methodical approach to improve the welfare of human
Human
Humans are the only living species in the Homo genus...

ity by learning to control nature. As such, speculation about metaphysics
Metaphysics
Metaphysics is a branch of philosophy concerned with explaining the fundamental nature of being and the world, although the term is not easily defined. Traditionally, metaphysics attempts to answer two basic questions in the broadest possible terms:...

, which can not be used for anything practical, and which can never be confirmed against the reality we experience, started to be deliberately avoided, especially according to the so called "empiricist" arguments of philosophers such as Bacon
Francis Bacon
Francis Bacon, 1st Viscount St Albans, KC was an English philosopher, statesman, scientist, lawyer, jurist, author and pioneer of the scientific method. He served both as Attorney General and Lord Chancellor of England...

, Hobbes, Locke
John Locke
John Locke FRS , widely known as the Father of Liberalism, was an English philosopher and physician regarded as one of the most influential of Enlightenment thinkers. Considered one of the first of the British empiricists, following the tradition of Francis Bacon, he is equally important to social...

 and Hume
David Hume
David Hume was a Scottish philosopher, historian, economist, and essayist, known especially for his philosophical empiricism and skepticism. He was one of the most important figures in the history of Western philosophy and the Scottish Enlightenment...

. The Latin motto "nihil in intellectu nisi prius fuerit in sensu" (nothing in the intellect without first being in the senses) has been described as the "guiding principle of empiricism" in the Oxford Dictionary of Philosophy. (This was in fact an old Aristotelian doctrine, which they took up, but as discussed above Aristotelians still believed that the senses on their own were not enough to explain the mind.)

These philosophers explain the intellect as something developed from experience of sensations, being interpreted by the brain in a physical way, and nothing else, which means that absolute knowledge is impossible. For Bacon, Hobbes and Locke, who wrote in both English and Latin, "intellectus" was translated as "understanding". Far from seeing it as secure way to perceive the truth about reality, Bacon, for example, actually named the intellectus in his Novum Organum
Novum Organum
The Novum Organum, full original title Novum Organum Scientiarum, is a philosophical work by Francis Bacon, written in Latin and published in 1620. The title translates as new instrument, i.e. new instrument of science. This is a reference to Aristotle's work Organon, which was his treatise on...

, and the proœmium to his Great Instauration, as a major source of wrong conclusions, because it is biased in many ways, for example towards over-generalizing. For this reason, modern science should be methodical, in order not to be misled by the weak human intellect. He felt that lesser known Greek philosophers such as Democritus
Democritus
Democritus was an Ancient Greek philosopher born in Abdera, Thrace, Greece. He was an influential pre-Socratic philosopher and pupil of Leucippus, who formulated an atomic theory for the cosmos....

 "who did not suppose a mind or reason in the frame of things", have been arrogantly dismissed because of Aristotelianism leading to a situation in his time wherein "the search of the physical causes hath been neglected, and passed in silence".

The intellect or understanding was the subject of Locke's Essay Concerning Human Understanding. These philosophers also tended not to emphasize the distinction between reason and intellect, describing the peculiar universal or abstract definitions of human understanding as being man-made and resulting from reason itself. In the case of Hume the distinctness or peculiarly of human understanding and reason, compared to other types of associative or imaginative thinking found in some other animals, are even questioned. In modern science during this time, Newton
Isaac Newton
Sir Isaac Newton PRS was an English physicist, mathematician, astronomer, natural philosopher, alchemist, and theologian, who has been "considered by many to be the greatest and most influential scientist who ever lived."...

 is sometimes described as more empiricist compared to Leibniz.

On the other hand, into modern times some philosophers have continued to propose that the human mind has an in-born ("a priori") ability to know the truth conclusively, and these need to argue that the human mind has direct and intuitive ideas about nature, and this means it can not be limited entirely to what can be known from sense perception. Amongst the early modern philosophers some such as Descartes, Spinoza, Leibniz, and Kant
KANT
KANT is a computer algebra system for mathematicians interested in algebraic number theory, performing sophisticated computations in algebraic number fields, in global function fields, and in local fields. KASH is the associated command line interface...

, tend to be distinguished from the empiricists as rationalists, and to some extent at least some of them are called idealists, and their writings on the intellect or understanding present various doubts about empiricism, and in some cases they argued for positions which appear more similar to those of medieval and classical philosophers.

The first in this series of modern rationalists, Descartes, is credited with defining a "mind-body problem" which is a major subject of discussion for university philosophy courses. According to the presentation his 2nd Meditation, the human mind and body are different in kind, and while the human body works like a clockwork mechanism, and its workings include memory and imagination, the real human is the thinking being, a soul. Descartes explicitly refused to divide this soul into its traditional parts such as intellect and reason, saying that these things were indivisible aspects of the soul. Descartes was therefore a dualist, but very much in opposition to traditional Aristotelian dualism. In his 6th Meditation he deliberately uses traditional terms and states that his active faculty of giving ideas to his thought must be corporeal, because the things perceived are clearly external to his own thinking and corporeal, while his passive faculty must be incorporeal (unless God is deliberately deceiving us, and then in this case the active faculty would be from God). This is the opposite of the traditional explanation found for example in Alexander of Aphrodisias and discussed above, for whom the passive intellect is material, while the active intellect is not. One result is that in many Aristotelian conceptions of the nous, for example that of Thomas Aquinas
Thomas Aquinas
Thomas Aquinas, O.P. , also Thomas of Aquin or Aquino, was an Italian Dominican priest of the Catholic Church, and an immensely influential philosopher and theologian in the tradition of scholasticism, known as Doctor Angelicus, Doctor Communis, or Doctor Universalis...

, the senses are still a source of all the intellect's conceptions. However, with the strict separation of mind and body proposed by Descartes, it becomes possible to propose that there can be thought about objects never perceived with the body's senses, such as a thousand sided geometrical figure. Gassendi
Pierre Gassendi
Pierre Gassendi was a French philosopher, priest, scientist, astronomer, and mathematician. With a church position in south-east France, he also spent much time in Paris, where he was a leader of a group of free-thinking intellectuals. He was also an active observational scientist, publishing the...

 objected to this distinction between the imagination and the intellect in Descartes. Hobbes also objected, and according to his own philosophical approach asserted that the "triangle in the mind comes from the triangle we have seen" and "essence
Essence
In philosophy, essence is the attribute or set of attributes that make an object or substance what it fundamentally is, and which it has by necessity, and without which it loses its identity. Essence is contrasted with accident: a property that the object or substance has contingently, without...

 in so far as it is distinguished from existence
Existence
In common usage, existence is the world we are aware of through our senses, and that persists independently without them. In academic philosophy the word has a more specialized meaning, being contrasted with essence, which specifies different forms of existence as well as different identity...

 is nothing else than a union of names by means of the verb is". Descartes, in his reply to this objection insisted that this traditional distinction between essence and existence is "known to all".

His contemporary Blaise Pascal
Blaise Pascal
Blaise Pascal , was a French mathematician, physicist, inventor, writer and Catholic philosopher. He was a child prodigy who was educated by his father, a tax collector in Rouen...

, criticised him in similar words to those used by Plato's Socrates concerning Anaxagoras, discussed above, saying that "I cannot forgive Descartes; in all his philosophy, Descartes did his best to dispense with God. But Descartes could not avoid prodding God to set the world in motion with a snap of his lordly fingers; after that, he had no more use for God."

Descartes argued that when the intellect does a job of helping people interpret what they perceive, not with the help of an intellect which enters from outside, but because each human mind comes into being with innate God-given ideas, more similar then, to Plato's theory of anamnesis, only not requiring reincarnation
Reincarnation
Reincarnation best describes the concept where the soul or spirit, after the death of the body, is believed to return to live in a new human body, or, in some traditions, either as a human being, animal or plant...

. Apart from such examples as the geometrical definition of a triangle, another example is the idea of God, according to the 3rd
Meditation. Error, according to the 4th Meditation, comes about because people make judgments about things which are not in the intellect or understanding. This is possible because the human will
Will (philosophy)
Will, in philosophical discussions, consonant with a common English usage, refers to a property of the mind, and an attribute of acts intentionally performed. Actions made according to a person's will are called "willing" or "voluntary" and sometimes pejoratively "willful"...

, being free, is not limited like the human intellect.

Spinoza, though considered a Cartesian and a rationalist, rejected Cartesian dualism and idealism. In his "pantheistic" approach, explained for example in his
Ethics, God is the same as nature, the human intellect is just the same as the human will. The divine intellect of nature is quite different from human intellect, because it is finite, but Spinoza does accept that the human intellect is a part of the infinite divine intellect.

Leibniz, in comparison to the guiding principle of the empiricists described above, added some words ""
nihil in intellectu nisi prius fuerit in sensu, nisi intellectus ipsi" (nothing in the intellect without first being in the senses except the intellect itself). Despite being at the forefront of modern science, and modernist philosophy, in his writings he still referred to the active and passive intellect, a divine intellect, and the immortality of the active intellect.

Berkeley
George Berkeley
George Berkeley , also known as Bishop Berkeley , was an Irish philosopher whose primary achievement was the advancement of a theory he called "immaterialism"...

, partly in reaction to Locke, also attempted to reintroduce an "immaterialism" into early modern philosophy (later referred to as "subjective idealism" by others). He argued that individuals can only know sensations and ideas of objects, not abstractions such as "matter", and that ideas depend on perceiving minds for their very existence. This belief later became immortalized in the dictum, "esse est percipi" ("to be is to be perceived"). As in classical and medieval philosophy, Berkeley believed understanding had to be explained by divine intervention, and that all our ideas are put in our mind by God.

Hume accepted some of Berkeley's corrections of Locke, but in answer insisted, as had Bacon and Hobbes, that absolute knowledge is not possible, and that all attempts to show how it could be possible have logical problems. Hume's writings remain highly influential on all philosophy afterwards, and for example considered by Kant to have shaken him from an intellectual slumber.

Kant, a turning point in modern philosophy, agreed with some classical philosophers and Leibniz that the intellect itself, although it needed sensory experience for understanding to begin, needs something else in order to make sense of the incoming sense information. In his formulation the intellect (Verstand) has "a priori" or innate principles which it has before thinking even starts. Kant represents the starting point of German idealism
German idealism
German idealism was a philosophical movement that emerged in Germany in the late 18th and early 19th centuries. It developed out of the work of Immanuel Kant in the 1780s and 1790s, and was closely linked both with romanticism and the revolutionary politics of the Enlightenment...

 and a new phase of modernity, while empiricist philosophy has also continued beyond Hume to the present day.

More recent modern philosophy and science


One of the results of the early modern philosophy has been the increasing creation of specialist fields of science, in areas that were once considered part of philosophy, and infant cognitive development
Infant cognitive development
The cognitive development of infants is the part of developmental psychology that studies the internal mental states of infants and very young children...

 and perception
Perception
Perception is the process of attaining awareness or understanding of the environment by organizing and interpreting sensory information. All perception involves signals in the nervous system, which in turn result from physical stimulation of the sense organs...

 now tend to be discussed now more within the sciences of psychology
Psychology
Psychology is the study of the mind and behavior. Its immediate goal is to understand individuals and groups by both establishing general principles and researching specific cases. For many, the ultimate goal of psychology is to benefit society...

 and neuroscience
Neuroscience
Neuroscience is the scientific study of the nervous system. Traditionally, neuroscience has been seen as a branch of biology. However, it is currently an interdisciplinary science that collaborates with other fields such as chemistry, computer science, engineering, linguistics, mathematics,...

 than in philosophy.

Modern mainstream thinking on the mind is not dualist, and sees anything innate in the mind as being a result of genetic and developmental factors which allow the mind to develop. Overall it accepts far less innate "knowledge" (or clear pre-dispositions to particular types of knowledge) than most of the classical and medieval theories derived from philosophers such as Plato, Aristotle, Plotinus and Al Farabi.

Apart from discussions about the history of philosophical discussion on this subject, contemporary philosophical discussion concerning this point has continued concerning what the ethical implications are of the different alternatives still considered likely.

See also

  • Gestalt psychology
    Gestalt psychology
    Gestalt psychology or gestaltism is a theory of mind and brain of the Berlin School; the operational principle of gestalt psychology is that the brain is holistic, parallel, and analog, with self-organizing tendencies...

  • Cognitive psychology
    Cognitive psychology
    Cognitive psychology is a subdiscipline of psychology exploring internal mental processes.It is the study of how people perceive, remember, think, speak, and solve problems.Cognitive psychology differs from previous psychological approaches in two key ways....

  • Perceptual psychology
    Perceptual psychology
    Perceptual psychology is a subfield of cognitive psychology that is concerned specifically with the pre-conscious innate aspects of the human cognitive system: perception....

  • Perception
    Perception
    Perception is the process of attaining awareness or understanding of the environment by organizing and interpreting sensory information. All perception involves signals in the nervous system, which in turn result from physical stimulation of the sense organs...

  • Superman
    Superman
    Superman is a fictional comic book superhero appearing in publications by DC Comics, widely considered to be an American cultural icon. Created by American writer Jerry Siegel and Canadian-born American artist Joe Shuster in 1932 while both were living in Cleveland, Ohio, and sold to Detective...

  • Noosphere
    Noosphere
    Noosphere , according to the thought of Vladimir Vernadsky and Teilhard de Chardin, denotes the "sphere of human thought". The word is derived from the Greek νοῦς + σφαῖρα , in lexical analogy to "atmosphere" and "biosphere". Introduced by Pierre Teilhard de Chardin 1922 in his Cosmogenesis"...

  • Demiurge
    Demiurge
    The demiurge is a concept from the Platonic, Neopythagorean, Middle Platonic, and Neoplatonic schools of philosophy for an artisan-like figure responsible for the fashioning and maintenance of the physical universe. The term was subsequently adopted by the Gnostics...

  • Buddhi
    Buddhi
    Buddhi is a feminine Sanskrit noun derived from the same root as the more familiar masculine form Buddha Buddhi is a feminine Sanskrit noun derived from the same root as the more familiar masculine form Buddha Buddhi is a feminine Sanskrit noun derived from the same root as the more familiar...

  • Saṃjñā
    Samjna
    Saṃjñā and sañña can be translated as "perception" or "cognition."-In the Early Buddhist literature:...

  • Truthiness
    Truthiness
    Truthiness is a "truth" that a person claims to know intuitively "from the gut" or that it "feels right" without regard to evidence, logic, intellectual examination, or facts....


External links

  • Definition of nous on Perseus Project
    Perseus Project
    The Perseus Project is a digital library project of Tufts University that assembles digital collections of humanities resources. It is hosted by the Department of Classics. It has suffered at times from computer hardware problems, and its resources are occasionally unavailable...

     website.
  • Aristotle's Psychology from the Stanford Encyclopedia of Philosophy
    Stanford Encyclopedia of Philosophy
    The Stanford Encyclopedia of Philosophy is a freely-accessible online encyclopedia of philosophy maintained by Stanford University. Each entry is written and maintained by an expert in the field, including professors from over 65 academic institutions worldwide...

  • What is the Human Nous? by John Romanides