Theodoric of Freiberg was a
GermanGermany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
member of the
Dominican orderThe Order of Preachers , after the 15th century more commonly known as the Dominican Order or Dominicans, is a Catholic religious order founded by Saint Dominic and approved by Pope Honorius III on 22 December 1216 in France...
and a
theologianTheology is the systematic and rational study of religion and its influences and of the nature of religious truths, or the learned profession acquired by completing specialized training in religious studies, usually at a university or school of divinity or seminary.-Definition:Augustine of Hippo...
and
physicistA physicist is a scientist who studies or practices physics. Physicists study a wide range of physical phenomena in many branches of physics spanning all length scales: from sub-atomic particles of which all ordinary matter is made to the behavior of the material Universe as a whole...
. He was named
provincialA Provincial Superior is a major superior of a religious order acting under the order's Superior General and exercising a general supervision over all the members of that order in a territorial division of the order called a province--similar to but not to be confused with an ecclesiastical...
of the Dominican Order in 1293, Albert the Great's old post.
Physics
While 13th century authors failed to provide an explanation for the
rainbowA rainbow is an optical and meteorological phenomenon that causes a spectrum of light to appear in the sky when the Sun shines on to droplets of moisture in the Earth's atmosphere. It takes the form of a multicoloured arc...
, at the turn of the fourteenth century Theodoric was able to give the first correct
geometricalGeometry arose as the field of knowledge dealing with spatial relationships. Geometry was one of the two fields of pre-modern mathematics, the other being the study of numbers ....
analysisAnalysis is the process of breaking a complex topic or substance into smaller parts to gain a better understanding of it. The technique has been applied in the study of mathematics and logic since before Aristotle , though analysis as a formal concept is a relatively recent development.The word is...
of this phenomenon, which was
"probably the most dramatic development of 14th- and 15th-century opticsOptics is the branch of physics which involves the behavior and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behavior of visible, ultraviolet, and infrared light...
".
Drawing from his two earlier works on light and colour, he wrote
De iride et radialibus impressionibus (
On the Rainbow and the impressions created by irradiance, c. 1304-1311), relying on geometry,
experimentAn experiment is a methodical procedure carried out with the goal of verifying, falsifying, or establishing the validity of a hypothesis. Experiments vary greatly in their goal and scale, but always rely on repeatable procedure and logical analysis of the results...
,
falsificationFalsifiability or refutability of an assertion, hypothesis or theory is the logical possibility that it can be contradicted by an observation or the outcome of a physical experiment...
and other methods. Among other properties he explained in detail:
- the colors of the primary and secondary rainbows
- the positions of the primary and secondary rainbows
- the path of sunlight within a drop: lightbeams are refracted
Refraction is the change in direction of a wave due to a change in its speed. It is essentially a surface phenomenon . The phenomenon is mainly in governance to the law of conservation of energy. The proper explanation would be that due to change of medium, the phase velocity of the wave is changed...
when entering the atmospheric droplets, then reflectedReflection is the change in direction of a wavefront at an interface between two differentmedia so that the wavefront returns into the medium from which it originated. Common examples include the reflection of light, sound and water waves...
inside the droplets and finally refracted again when leaving them.
- the formation of the rainbow: he explains the role of the individual drops in creating the rainbow
- the phenomenon of color reversal in the secondary rainbow
Using spherical flasks and glass globes filled with water, Freiberg was able to simulate the water droplets during rainfall. Still in its early stages, experimental instrumentation would later expand to be used primarily for making measurements, extending the human senses and creating and isolated environment for the experimenter. During his experimentation with these glass globes, Freiberg was correct in asserting that the colors formed in interaction with the water droplets.
Recently, scientists have found evidence of the experimental instrumentation used by Freiberg. Currently on loan to Universities in Providence, Rhode Island, the instrumentation does, indeed, simulate the droplet of water which the rainbow is reflected through.
One of his contemporaries, Kamal al-Din al-Farisi, offered the same experimentally-established explanation of the rainbow (without any contacts between them) in his
Kitab tanqih al-manazir (
The Revision of the Optics). Both authors however relied on the
Book of OpticsThe Book of Optics ; ; Latin: De Aspectibus or Opticae Thesaurus: Alhazeni Arabis; Italian: Deli Aspecti) is a seven-volume treatise on optics and other fields of study composed by the medieval Muslim scholar Alhazen .-See also:* Science in medieval Islam...
by Ibn al-Haytham (Alhacen)/ Alhazen.
Theology
Dietrich's theological works tend to be heavily Neoplatonic, while his more secular philosophical works are more
AristotelianAristotle 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...
. Dietrich disagreed with
Thomas AquinasThomas 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...
on certain metaphysical issues, and seems to have written in opposition to particular works by Aquinas.
He had a remarkable influence on the 10 years younger
Meister EckhartEckhart von Hochheim O.P. , commonly known as Meister Eckhart, was a German theologian, philosopher and mystic, born near Gotha, in the Landgraviate of Thuringia in the Holy Roman Empire. Meister is German for "Master", referring to the academic title Magister in theologia he obtained in Paris...
, mainly via the treatises
De visione beatifica (
Of the beatific vision) and
De intellectu et intelligibili (
Of the intellect and the intelligible), and one of his extraordinary contributions to
medieval philosophyMedieval philosophy is the philosophy in the era now known as medieval or the Middle Ages, the period roughly extending from the fall of the Western Roman Empire in the fifth century AD to the Renaissance in the sixteenth century...
was a theory of the
soulA 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...
that equalled the Aristotelian notion of "
agent intellectOn 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...
" and the
AugustinianAugustine 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...
notion of "abditum mentis" (i.e. the hiddenness, or hidden place of the soul).
The theory of the agent intellect says that in knowing, the mind is not merely passive, it has to work on producing a conception of its object, a conception which is then received and retained by the passive part of the mind. The hiddenness of the soul, in turn, is the ground of the soul in which
GodGod 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....
's image is imprinted, a spiritual apex of man's being by which he transcends space and time.
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