An Unsolved Riddle

In 1688, John Locke received a letter from scientist William Molyneaux posing a curious philosophical riddle: Suppose a blind man learned to identify a cube and a sphere by touch. If the shapes were then laid before him and his vision restored, could he identify them by sight alone?

blind_man_with_cane

Three hundred years later, it’s still an open question (Locke agreed with Molyneaux that the answer is probably no).