In 1688, the Irish scientist and politician William Molyneux sent a letter to the well-known philosopher John Locke in which he posed a mystery that aroused the interest of the entire scientific community of the time. Is about a thought experiment known as Molyneux’s Problem and still arouses interest today.
Throughout this article we will talk about this issue that is debated and discussed both in the field of medicine and philosophy and that still today generates numerous disagreements between researchers and thinkers.
Throughout his career, Molyneux was especially interested in the mysteries of optics and the psychology of sight. The main reason for this is that his own wife lost her sight when she was still very young.
The main question that the scientist posed was whether a person born blind who over time has learned to distinguish and name different objects by touch he would be able to recognize them with his sight if at some point in his life he recovered it.
The background that led Molyneux to ask this question was inspired by a writing by the philosopher John Locke in which he made a distinction between the ideas or concepts that we acquire through a single sense and those others for which we need more than one type of perception. .
Since Molyneux was a great admirer of this English intellectual, he decided to send him his reflections by postal mail… which, at first, received no response. However, two years later, with the recent friendship between these two thinkers, Locke decided to answer, also, with great enthusiasm.
He included Molyneux’s Problem in his work, making it possible for this reflection to reach a much wider audience
Locke exemplified this issue in the following way: a man blind from birth learns to distinguish by touch a cube and a sphere made of the same materials and of the same size. Now suppose that this man regains his sight and both objects are placed in front of you, could you then distinguish and name them without touching them first, only with your eyesight?
Molyneux’s Problem attracted the attention of numerous philosophers at that time, most of them becoming references today. Among them were Berkeley, Leibniz, William James and Voltaire himself.
The first discussions of the time
The first reactions of the philosophers of the time denied, first of all, the possibility that a person blind from birth could acquire sight, so considered Molyneux’s Problem as a kind of mental challenge that could only be solved through reason.
They all agreed that the sensations perceived by the senses of sight and touch differ from each other, but they managed to establish an agreement about how they were related. Some of them, like Berkeley, thought that this relationship was arbitrary and could only be based on experience.
However, some determined that this relationship was necessary and based on innate knowledge, while others, such as Molyneux and Locke themselves, thought that this relationship was necessary and learned through experience.
Once the opinions and thoughts of each and every one of these philosophers were compiled, it was seen that all those who belonged to the empiricist current of philosophy of the time, like Molyneux, Locke and Berkeley, responded in the negative: the blind man would not be able to associate what he was seeing, on the one hand, with what he once touched, on the other. In contrast, those who followed rationalist positions tended to give affirmative answers, so there was no way to achieve a unanimous solution.
Some philosophers thought that a person deprived of the sense of sight from birth could respond directly at the moment he could observe objects. However, the rest believed that the person would need to use their memory and reason, and that they should even be able to observe all sides of objects by walking around them.
What do the studies say?
Despite the impossibility of carrying out scientific studies that could solve the Molyneux Problem, in 1728, The English anatomist William Cheselden published the case of a child with congenital blindness that he had been able to see after cataract surgery.
Throughout this case it is explained that when the child was able to see for the first time, he was not able to recognize, through sight, the shape of things, and that he could not differentiate between various objects.
Some philosophers, including Voltaire, Camper and Berkeley, considered the English doctor’s observations to be evident and irrefutable, thus confirming the hypothesis that a blind person who regains sight is not capable of differentiating objects until they learn to see.
However, others were skeptical of this evidence. They considered that it was possible that the child had not been able to make valid value judgments because his eyes still weren’t working properly and that it was necessary to give him a little time to recover. Others also pointed out that the boy’s intelligence could also influence the validity of his answers.
Modern approaches to the thought experiment
Throughout the 19th century, all kinds of stories and studies about patients undergoing cataract surgery were published that attempted to shed some light on Molyneux’s Problem. As expected, results of all kinds appeared, some in favor of Cheselden’s results and others against. Furthermore, these cases were impossible to compare, since the pre- and postoperative circumstances were quite different. As a consequence, the Molyneux Problem was debated very frequently, without reaching any agreement on its solution.
As for the Molyneux Problem in the 20th century, it focused on historical reviews and biographies of those philosophers who analyzed it and proposed solutions for it. Over the years, This enigma has come to encompass all types of scientific fields such as psychology, ophthalmology, neurophysiology and even mathematics and art.
In 1985, with the incorporation of new technologies in the health field, another variation of the Molyneux Problem was proposed. This questioned whether the visual cortex of a congenitally blind patient could be electrically stimulated in a way in which the patient perceived a pattern of flashes of light in the shape of a cube or sphere However, even with these methods it has not been possible to establish a secure answer to the question.
The problem that could never be solved
We are quite sure that at no time was Molyneux aware of the stir his question would cause throughout history. In this sense, it can be concluded that the Molyneux Problem is one of the most fruitful and productive mental experiments proposed throughout the history of philosophy, which remains shrouded in the same mystery as when Molyneux raised it in 1688
