Experience and the limits of understanding › The Molyneux Problem: A Thought Experiment

In Book II, chapter IX, Locke includes William Molyneux's question: suppose a person born blind has learned to distinguish a cube from a sphere by touch and then acquires sight. Could that person identify which is which by sight alone, before touching them? Locke agrees with Molyneux that the answer is no. The man has ideas of cube and sphere derived from touch, but these are different from the ideas he would get from sight. He would need experience to learn how his tactile ideas correspond to his visual ideas. The point of the example is narrower than a general claim that vision teaches us nothing. It asks whether the connection between a familiar tactile distinction and a newly available visual distinction would be immediately known. Locke uses the problem to examine how experience contributes to what perception seems to present directly.