Molyneux's problem

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Different shaped stress balls, including a cube, a star, and a sphere

Molyneux's problem is a thought experiment in philosophy [1] concerning immediate recovery from blindness. It was first formulated by William Molyneux, and notably referred to in John Locke's An Essay Concerning Human Understanding (1689). The problem can be stated in brief, "if a man born blind can feel the differences between shapes such as spheres and cubes, could he, if given the ability to see, distinguish those objects by sight alone, in reference to the tactile schemata he already possessed?"

Contents

Molyneux and Locke

The question was originally posed to Locke by philosopher William Molyneux, whose wife was blind. [2] It is known from the report of it in Locke's Essay Concerning Human Understanding , which is reproduced here:

I shall here insert a problem of that very ingenious and studious promoter of real knowledge, the learned and worthy Mr. Molineux, which he was pleased to send me in a letter some months since; and it is this:—“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 the sphere. Suppose then the cube and sphere placed on a table, and the blind man be made to see: quaere, 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, how a cube affects his touch, yet he has not yet obtained the experience, that what affects his touch so or so, must affect his sight so or so; or that a protuberant angle in the cube, that pressed his hand unequally, shall appear to his eye as it does in the cube.”—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. [3]

Before Locke

A similar problem was also addressed earlier in the 12th century by Ibn Tufail (Abubacer), in his philosophical novel, Hayy ibn Yaqdhan (Philosophus Autodidactus). This version focused on colors rather than shapes, and gave the opposite solution: [4] [5]

If you want a comparison that will make you clearly grasp the difference between the perception, such as it is understood by that sect [the Sufis] and the perception as others understand it, imagine a person born blind, endowed however with a happy natural temperament, with a lively and firm intelligence, a sure memory, a straight sprite, who grew up from the time he was an infant in a city where he never stopped learning, by means of the senses he did dispose of, to know the inhabitants individually, the numerous species of beings, living as well as non-living, there, the streets and sidestreets, the houses, the steps, in such a manner as to be able to cross the city without a guide, and to recognize immediately those he met; the colors alone would not be known to him except by the names they bore, and by certain definitions that designated them. Suppose that he had arrived at this point and suddenly, his eyes were opened, he recovered his view, and he crosses the entire city, making a tour of it. He would find no object different from the idea he had made of it; he would encounter nothing he didn’t recognize, he would find the colors conformable to the descriptions of them that had been given to him; and in this there would only be two new important things for him, one the consequence of the other: a clarity, a greater brightness, and a great voluptuousness.

After Locke

Early modern period

In 1709, in §95 of An Essay Towards a New Theory of Vision, George Berkeley 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.

Leibniz (German philosopher, 1646–1716) also discussed this problem, but derived a different answer. He suggested that the two sets of experience have one element in common, that is, extension. Hence it is possible to infer from one type of idea to another. [1]

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.

Current research on human vision

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. In 1971, Alberto Valvo estimated that fewer than twenty cases have been known in the last 1000 years. [6]

In 2003, Pawan Sinha, a professor at the Massachusetts Institute of Technology, set up a program in the framework of the Project Prakash [7] and eventually had the opportunity to find five individuals who satisfied the requirements for an experiment aimed at answering Molyneux's question experimentally. Prior to treatment, the subjects (aged 8 to 17) were only able to discriminate between light and dark, with two of them also being able to determine the direction of a bright light. The surgical treatments took place between 2007 and 2010, and quickly brought the relevant subject from total congenital blindness to fully seeing. A carefully designed test was submitted to each subject within the next 48 hours. Based on its result, the experimenters concluded that the answer to Molyneux's problem is, in short, "no". Although after restoration of sight, the subjects could distinguish between objects visually almost as effectively as they would do by touch alone, they were unable to form the connection between an object perceived using the two different senses. The correlation was barely better than if the subjects had guessed. They had no innate ability to transfer their tactile shape knowledge to the visual domain. However, the experimenters could test three of the five subjects on later dates (5 days, 7 days, and 5 months after, respectively) and found that the performance in the touch-to-vision case improved significantly, reaching 80–90%. [8] [9] [10]

Ostrovsky, et al., [11] in 2006, 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.

Regarding Molyneux's problem, the authors Asif A. Ghazanfar & Hjalmar K. Turesson (2008) have recently noted that there are not separate brain processes for motor outputs and individual sensory modalities, but rather that the brain uses all available context-specific information to act – that is, all information associated with a specific action. [12] They suggest that this makes Molyneux's problem into an ill-posed question, from a neuroscientific perspective, since Molyneux does not suggest an action to be done with the cube and the globe. [12]

Research on chicken vision

In 2024, chickens were reared from incubation and hatching in total darkness, then exposed in said darkness to objects of either smooth or bumpy textures for 24 hours. They were then tested on visual recognition of the objects as they first experienced light. Upon first sight, chicks that touched the smooth objects approached the smooth objects much more often than chicks that touched bumpy objects did. [13]

See also

Related Research Articles

<span class="mw-page-title-main">Empiricism</span> Idea that knowledge comes only/mainly from sensory experience

In philosophy, empiricism is an epistemological view which holds that true knowledge or justification comes only or primarily from sensory experience and empirical evidence. It is one of several competing views within epistemology, along with rationalism and skepticism. Empiricists argue that empiricism is a more reliable method of finding the truth than purely using logical reasoning, because humans have cognitive biases and limitations which lead to errors of judgement. Empiricism emphasizes the central role of empirical evidence in the formation of ideas, rather than innate ideas or traditions. Empiricists may argue that traditions arise due to relations of previous sensory experiences.

<span class="mw-page-title-main">George Berkeley</span> Anglo-Irish philosopher and bishop (1685–1753)

George Berkeley – known as Bishop Berkeley – was an Anglo-Irish philosopher whose primary achievement was the advancement of a theory he called "immaterialism". This theory denies the existence of material substance and instead contends that familiar objects like tables and chairs are ideas perceived by the mind and, as a result, cannot exist without being perceived. Berkeley is also known for his critique of abstraction, an important premise in his argument for immaterialism.

<span class="mw-page-title-main">Philosophy of perception</span> Branch of philosophy

The philosophy of perception is concerned with the nature of perceptual experience and the status of perceptual data, in particular how they relate to beliefs about, or knowledge of, the world. Any explicit account of perception requires a commitment to one of a variety of ontological or metaphysical views. Philosophers distinguish internalist accounts, which assume that perceptions of objects, and knowledge or beliefs about them, are aspects of an individual's mind, and externalist accounts, which state that they constitute real aspects of the world external to the individual. The position of naïve realism—the 'everyday' impression of physical objects constituting what is perceived—is to some extent contradicted by the occurrence of perceptual illusions and hallucinations and the relativity of perceptual experience as well as certain insights in science. Realist conceptions include phenomenalism and direct and indirect realism. Anti-realist conceptions include idealism and skepticism. Recent philosophical work have expanded on the philosophical features of perception by going beyond the single paradigm of vision.

<span class="mw-page-title-main">Idea</span> Mental image or concept

In common usage and in philosophy, ideas are the results of thought. Also in philosophy, ideas can also be mental representational images of some object. Many philosophers have considered ideas to be a fundamental ontological category of being. The capacity to create and understand the meaning of ideas is considered to be an essential and defining feature of human beings.

<span class="mw-page-title-main">Subjective idealism</span> Philosophy that only minds and ideas are real

Subjective idealism, or empirical idealism or immaterialism, is a form of philosophical monism that holds that only minds and mental contents exist. It entails and is generally identified or associated with immaterialism, the doctrine that material things do not exist. Subjective idealism rejects dualism, neutral monism, and materialism; it is the contrary of eliminative materialism, the doctrine that all or some classes of mental phenomena do not exist, but are sheer illusions.

Astereognosis is the inability to identify an object by active touch of the hands without other sensory input, such as visual or sensory information. An individual with astereognosis is unable to identify objects by handling them, despite intact elementary tactile, proprioceptive, and thermal sensation. With the absence of vision, an individual with astereognosis is unable to identify what is placed in their hand based on cues such as texture, size, spatial properties, and temperature. As opposed to agnosia, when the object is observed visually, one should be able to successfully identify the object.

<span class="mw-page-title-main">Ibn Tufayl</span> Arab Andalusian Muslim polymath (c. 1105–1185)

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<span class="mw-page-title-main">William Molyneux</span> Anglo-Irish philosopher

William MolyneuxFRS was an Anglo-Irish writer on science, politics and natural philosophy.

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Recovery from blindness is the phenomenon of a blind person gaining the ability to see, usually as a result of medical treatment. As a thought experiment, the phenomenon is usually referred to as Molyneux's problem. It is often stated that the first published human case was reported in 1728 by the surgeon William Cheselden. However, there is no evidence that Cheselden's patient, a boy named Daniel Dolins, actually recovered any vision. Patients who experience dramatic recovery from blindness experience significant to total agnosia, having serious confusion with their visual perception.

<i>Hayy ibn Yaqdhan</i> Arabic philosophical novel and allegorical tale written by Ibn Tufail

Ḥayy ibn Yaqẓān is an Arabic philosophical novel and an allegorical tale written by Ibn Tufail in the early 12th century in Al-Andalus. Names by which the book is also known include the Latin: Philosophus Autodidactus ; and English: The Improvement of Human Reason: Exhibited in the Life of Hai Ebn Yokdhan. Ḥayy ibn Yaqẓān was named after an earlier Arabic philosophical romance of the same name, written by Avicenna during his imprisonment in the early 11th century, even though both tales had different stories. The novel greatly inspired Islamic philosophy as well as major Enlightenment thinkers. It is the third most translated text from Arabic, after the Quran and the One Thousand and One Nights.

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Apperceptive agnosia is a neurological disorder characterized by failures in recognition due to a failure of perception. In contrast, associative agnosia is a type of agnosia where perception occurs but recognition still does not occur. When referring to apperceptive agnosia, visual and object agnosia are most commonly discussed; this occurs because apperceptive agnosia is most likely to present visual impairments. However, in addition to visual apperceptive agnosia there are also cases of apperceptive agnosia in other sensory areas.

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<span class="mw-page-title-main">Philosophy of color</span> Dispute between color realism and fictionalism

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Mirror-touch synesthesia is a rare condition which causes individuals to experience a similar sensation in the same part or opposite part of the body that another person feels. For example, if someone with this condition were to observe someone touching their cheek, they would feel the same sensation on their own cheek. Synesthesia, in general, is described as a condition in which a concept or sensation causes an individual to experience an additional sensation or concept. Synesthesia is usually a developmental condition; however, recent research has shown that mirror touch synesthesia can be acquired after sensory loss following amputation.

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References

  1. 1 2 Bunnin, Nicholas; Yu, Jiyuan (2004). The Blackwell dictionary of Western philosophy. Malden, MA: Blackwell Pub. pp. 440–441. ISBN   978-1-4051-0679-5.
  2. ↑ "TO SEE AND NOT SEE". The New Yorker . Archived from the original on 2006-08-31. Retrieved 2010-05-04.
  3. ↑ "The Project Gutenberg eBook of An Essay Concerning Humane Understanding, Volume I., by John Locke". www.gutenberg.org. Retrieved 2024-04-16.
  4. ↑ Muhammad ibn Abd al-Malik Ibn Tufayl and Léon Gauthier (1981), Risalat Hayy ibn Yaqzan, p. 5, Editions de la Méditerranée:
  5. ↑ Diana Lobel (2006), A Sufi-Jewish Dialogue: Philosophy and Mysticism in Baḥya Ibn Paqūda's Duties of the Heart, p. 24, University of Pennsylvania Press, ISBN   0-8122-3953-9.
  6. ↑ Valvo, A. (1971). Sight restoration after long-term blindness: The problems and behavior patterns of visual rehabilitation. New York: American Foundation for the Blind.
  7. ↑ "Project Prakash". Project Prakash.
  8. ↑ Held, R.; Ostrovsky, Y.; De Gelder, B.; Gandhi, T.; Ganesh, S.; Mathur, U.; Sinha, P. (2011). "The newly sighted fail to match seen with felt". Nature Neuroscience. 14 (5): 551–553. doi:10.1038/nn.2795. PMID   21478887. S2CID   52849918.
  9. ↑ Crawford, Hayley (10 April 2011). "Mapping touch to sight takes time to learn". New Scientist.
  10. ↑ Trafton, Anne (10 April 2011). "Scientists settle centuries-old debate on perception". Medical Xpress.
  11. ↑ Ostrovsky, et al., 2006, "Vision following extended congenital blindness", Department of Brain and Cognitive Sciences Massachusetts Institute of Technology
  12. 1 2 Ghazanfar, A. A. & Turesson, H. K. (2008). Speech production: How does a word feel? Current Biology, 18,24: R1142–1144.
  13. ↑ Versace, Elisabetta; Freeland, Laura; Emmerson, Michael G. (3 April 2024). "First-sight recognition of touched objects shows that chicks can solve Molyneux's problem". Biology Letters. 20 (4). doi:10.1098/rsbl.2024.0025. ISSN   1744-957X. PMC   10987231 . PMID   38565149.

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