Molyneux's Problem
Encyclopedia
Molyneux's problem is a thought experiment
in philosophy concerning immediate recovery from blindness.
It was first formulated by William Molyneux
, and notably referenced in John Locke
's An Essay Concerning Human Understanding
.
The problem can be stated in brief, "if a man born blind can feel the differences between shape
s such as sphere
s and cube
s, could he similarly distinguish those objects by sight if given the ability to see?"
, whose wife was blind:
To which Locke responds in An Essay Concerning Human Understanding
:
also concluded that there was no necessary connection between a tactile world and a sight world—that a connection between them could be established only on the basis of experience.
He speculated:
In 1749, Denis Diderot
wrote Letter on the blind for the benefit of those who see as a criticism of our knowledge of ultimate reality.
Scientist and politician William Molyneux
proposed a problem in a correspondence with Locke that involves the differences between modes of perception
s and true understanding.
Locke himself believed that sight and touch were entirely different sense perceptions and thus the blind man could not distinguish the sphere from the cube at first sight.
A similar problem was also addressed earlier in the 12th century by Ibn Tufail
(Abubacer), in his philosophical novel
, Hayy ibn Yaqdhan
(Philosophus Autodidactus). His version of the problem, however, dealt mainly with color
s rather than shapes.
Regarding Molyneux's problem, the authors Asif A. Ghazanfar & Hjalmar K. Turesson (2008) have recently noted:
One reason that Molyneux's Problem could be posed in the first place is the extreme dearth of human subjects who gain vision after extended congenital blindness. Alberto Valvo estimated that less than twenty cases have been known in the last 1000 years. Ostrovsky, et al., studied a woman who gained sight at the age of 12 when she underwent surgery for dense bilateral congenital cataracts. They report that the subject could recognize family members by sight six months after surgery, but took up to a year to recognize most household objects purely by sight.
In 2003, Pawan Sinha, a professor at MIT in Boston, set up a program in India as a part of which he treated 5 patients that almost instantly took them from total congenital blindness to fully seeing. This provided a unique opportunity or answer the Molyneux's problem experimentally. Based on this study, on April 10, 2011, he concluded that the answer, in short, to the Molyneux's problem was "no". Although after restoration of sight, the subjects could distinguish between objects visually as effectively as they would do by touch alone, they were unable to form the connection between object perceived using the two different senses.
There is no ability of one sense to supply information to the other - in this case visual and tactile information. The results of the experiment were barely better than if the subjects had guessed.
Thought experiment
A thought experiment or Gedankenexperiment considers some hypothesis, theory, or principle for the purpose of thinking through its consequences...
in philosophy concerning immediate recovery from blindness.
It was first formulated by William Molyneux
William Molyneux
William Molyneux FRS was an Irish natural philosopher and writer on politics.He was born in Dublin to Samuel Molyneux , lawyer and landowner , and his wife, Anne, née Dowdall. The second of five children, William Molyneux came from a relatively prosperous Anglican background...
, and notably referenced in John 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...
's An Essay Concerning Human Understanding
An Essay Concerning Human Understanding
First appearing in 1690 with the printed title An Essay Concerning Humane Understanding, An Essay Concerning Human Understanding by John Locke concerns the foundation of human knowledge and understanding. He describes the mind at birth as a blank slate filled later through experience...
.
The problem can be stated in brief, "if a man born blind can feel the differences between shape
Shape
The shape of an object located in some space is a geometrical description of the part of that space occupied by the object, as determined by its external boundary – abstracting from location and orientation in space, size, and other properties such as colour, content, and material...
s such as sphere
Sphere
A sphere is a perfectly round geometrical object in three-dimensional space, such as the shape of a round ball. Like a circle in two dimensions, a perfect sphere is completely symmetrical around its center, with all points on the surface lying the same distance r from the center point...
s and cube
Cube
In geometry, a cube is a three-dimensional solid object bounded by six square faces, facets or sides, with three meeting at each vertex. The cube can also be called a regular hexahedron and is one of the five Platonic solids. It is a special kind of square prism, of rectangular parallelepiped and...
s, could he similarly distinguish those objects by sight if given the ability to see?"
Original correspondence
The question was originally posed to Locke by philosopher William MolyneuxWilliam Molyneux
William Molyneux FRS was an Irish natural philosopher and writer on politics.He was born in Dublin to Samuel Molyneux , lawyer and landowner , and his wife, Anne, née Dowdall. The second of five children, William Molyneux came from a relatively prosperous Anglican background...
, whose wife was blind:
Suppose a man born blind, and now adult, and taught by his touch to distinguish between a cube and a sphere of the same metal, and nighly of the same bigness, so as to tell, when he felt one and the other, which is the cube, which is the sphere. Suppose then the cube and the sphere placed on a table, and the blind man made to see: query, Whether by his sight, before he touched them, he could now distinguish and tell which is the globe, which the cube? To which the acute and judicious proposer answers: ‘Not. For though he has obtained the experience of how a globe, and how a cube, affects his touch; yet he has not yet attained the experience, that what affects his touch so or so, must affect his sight so or so…’
To which Locke responds in An Essay Concerning Human Understanding
An Essay Concerning Human Understanding
First appearing in 1690 with the printed title An Essay Concerning Humane Understanding, An Essay Concerning Human Understanding by John Locke concerns the foundation of human knowledge and understanding. He describes the mind at birth as a blank slate filled later through experience...
:
I agree with this thinking gentleman, whom I am proud to call my friend, in his answer to this problem; and am of opinion that the blind man, at first sight, would not be able with certainty to say which was the globe, which the cube, whilst he only saw them; though he could unerringly name them by his touch, and certainly distinguish them by the difference of their figures felt.
Responses
In 1709, in “A New Theory of Vision,” George BerkeleyGeorge Berkeley
George Berkeley , also known as Bishop Berkeley , was an Irish philosopher whose primary achievement was the advancement of a theory he called "immaterialism"...
also concluded that there was no necessary connection between a tactile world and a sight world—that a connection between them could be established only on the basis of experience.
He speculated:
the objects to which he had hitherto used to apply the terms up and down, high and low, were such as only affected or were in some way perceived by touch; but the proper objects of vision make a new set of ideas, perfectly distinct and different from the former, and which can in no sort make themselves perceived by touch (sect. 95).
In 1749, Denis Diderot
Denis Diderot
Denis Diderot was a French philosopher, art critic, and writer. He was a prominent person during the Enlightenment and is best known for serving as co-founder and chief editor of and contributor to the Encyclopédie....
wrote Letter on the blind for the benefit of those who see as a criticism of our knowledge of ultimate reality.
Scientist and politician William Molyneux
William Molyneux
William Molyneux FRS was an Irish natural philosopher and writer on politics.He was born in Dublin to Samuel Molyneux , lawyer and landowner , and his wife, Anne, née Dowdall. The second of five children, William Molyneux came from a relatively prosperous Anglican background...
proposed a problem in a correspondence with Locke that involves the differences between modes 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...
s and true understanding.
Locke himself believed that sight and touch were entirely different sense perceptions and thus the blind man could not distinguish the sphere from the cube at first sight.
A similar problem was also addressed earlier in the 12th century by Ibn Tufail
Ibn Tufail
Ibn Tufail was an Andalusian Muslim polymath: an Arabic writer, novelist, Islamic philosopher, Islamic theologian, physician, vizier,...
(Abubacer), in his philosophical novel
Philosophical novel
Philosophical fiction refers to works of fiction in which a significant proportion of the work is devoted to a discussion of the sort of questions normally addressed in discursive philosophy. These might include the function and role of society, the purpose of life, ethics or morals, the role of...
, Hayy ibn Yaqdhan
Hayy ibn Yaqdhan
Ḥayy ibn Yaqẓān is an Arabic philosophical novel and allegorical tale written by Ibn Tufail in the early 12th century.- Translations :* from Wikisource* English translations of Hayy bin Yaqzan...
(Philosophus Autodidactus). His version of the problem, however, dealt mainly with color
Color
Color or colour is the visual perceptual property corresponding in humans to the categories called red, green, blue and others. Color derives from the spectrum of light interacting in the eye with the spectral sensitivities of the light receptors...
s rather than shapes.
Regarding Molyneux's problem, the authors Asif A. Ghazanfar & Hjalmar K. Turesson (2008) have recently noted:
"Production of speech is seen as a pure motor act, involving muscles and the neurons controlling them, while perception of speech is seen as purely sensory, involving the ear and the auditory pathway. This parcellation of the systems appear intuitive and clear, but recent studies [beginning with Taine 1870!] ... suggest that such divisions may be fundamentally wrong. Rather than separate processes for motor outputs and individual sensory modalities, adaptive action seems to use all the available context-specific information. That is, neural representations across the brain may be centered on specific actions. This view on neural representations puts 'Molyneux's Problem' in a new light. Unisensory signals are fused into multisensory motor representations unified by an action, but since Molyneux does not suggest any action, his 'problem' may be better viewed as an ill-posed question -- at least from a neuroscientific perspective".
One reason that Molyneux's Problem could be posed in the first place is the extreme dearth of human subjects who gain vision after extended congenital blindness. Alberto Valvo estimated that less than twenty cases have been known in the last 1000 years. Ostrovsky, et al., studied a woman who gained sight at the age of 12 when she underwent surgery for dense bilateral congenital cataracts. They report that the subject could recognize family members by sight six months after surgery, but took up to a year to recognize most household objects purely by sight.
In 2003, Pawan Sinha, a professor at MIT in Boston, set up a program in India as a part of which he treated 5 patients that almost instantly took them from total congenital blindness to fully seeing. This provided a unique opportunity or answer the Molyneux's problem experimentally. Based on this study, on April 10, 2011, he concluded that the answer, in short, to the Molyneux's problem was "no". Although after restoration of sight, the subjects could distinguish between objects visually as effectively as they would do by touch alone, they were unable to form the connection between object perceived using the two different senses.
There is no ability of one sense to supply information to the other - in this case visual and tactile information. The results of the experiment were barely better than if the subjects had guessed.
See also
- Eşref ArmağanEsref ArmaganEşref Armağan is a blind painter of Turkish origin. He was born both unsighted and to an impoverished family. As a child and young adult he never received any formal schooling or training; however, he has taught himself to write and print. He draws and paints by using his hands and primarily oil...
- Unsolved problems in philosophyUnsolved problems in philosophyThis is a list of some of the major unsolved problems in philosophy. Clearly, unsolved philosophical problems exist in the lay sense . However, philosophers generally accord serious philosophical problems specific names or questions, which indicate a particular method of attack or line of reasoning...
- Mike May who recovered his vision late in life after losing it at the age of 3.
External links
- Molyneux's Problem, Stanford Encyclopedia of Philosophy