Medical Science Has Answered This 300-Year-Old Philosophy Question

If a person was blind from birth but had their vision restored, would that person be able to recognize by sight the objects they knew by touch? This is Molyneux's problem, and it's been a minor thorn in philosophers' sides since 1688. Modern medicine, however, may have come up with an answer.

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A Question Of Its Time

The thing about philosophy is that the questions that keep thinkers up at night are the ones on the fringes of what can be known at the time. In the late 1600s, Newton was pushing the boundaries and optics were all the rage, so it's not surprising that William Molyneux found himself obsessed with the ramifications of a cure for blindness. For him, the problem was more personal, however, as his wife was struck blind by an illness. He first posed the question to John Locke in a personal correspondence, and in doing sparked several centuries of debate. Locke believed that the answer was "no"—he believed interpreting sensory data was a learned experience, so a person who had known what a cube was only through touch would have to learn to recognize a cube by sight separately. Other philosophers, especially those in the Rationalist tradition such as Gottfried Liebniz, disagreed. The only thing that was missing? Any kind of empirical evidence.

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Science Catches Up To Philosophy

The thing is, these days the prospect of curing lifelong visual impairment is not merely hypothetical. It's still not super common, however, so a definitive answer was not forthcoming until M.I.T. professor of vision and computational neuroscience Pawan Sinha founded Project Prakash, a program to restore sight to children in India.

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Between 2007 and 2010, Project Prakash restored sight to five children who had been visually impaired from birth. After their surgeries, the children were give a test using small, Lego-like blocks. First, they were asked to match identical blocks by touch, and then to match identical blocks by sight. It was found that they could achieve both of these tasks—but they ran into problems when they were asked to match one they knew by touch to one they knew by sight. Over time, however, their ability to do so improved, and they also began to develop other visualization skills as well. In short, the verdict is in—Locke was right.

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Written by Ashley Hamer April 5, 2017