Molyneux's question : vision, touch, and the philosophy of perception / Michael J. Morgan.

  • Morgan, Michael J.
Date:
1977
Catalogue details

Licence: Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)

Credit: Molyneux's question : vision, touch, and the philosophy of perception / Michael J. Morgan. Source: Wellcome Collection.

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    MOLYNEUX'S QUESTION of a sense to make you realize the advantages of symbols to those senses that remain; and people who have the misfortune to be deaf, blind or dumb, or who lose these three senses by an accident, would be very grateful for a clear and precise haptic language. It is much more straightforward to use already invented symbols than to be their inventor — as one is forced by circumstances to be if one is deprived. What an advantage it would have been to Saunderson to find a 'palpable arithmetic' all ready for him at the age of five, instead of having to make one up at the age of twenty-five! This Saunderson, Madame, is another blind person whom it would not be irrelevant to consider here. Wondrous things are told about him, and his progress in literature and in the mathematical sciences lends credence to all of them. He used the same device for calculations and for drawing rectilinear figures. [A digit was represented by one or more pins placed in a 3 x 3 matrix of holes; a pin with a large head in the centre hole, with no other pins around, represented zero; a similarly placed pin with a small head represented unity; a large-headed pin in the centre with a small-headed one at 12 o'clock represented two, and so on going round the board clockwise. Saunderson had built for him a calculating machine in which large numbers of these matrices were arranged in rows and columns, for the representation of numbers. The arrangement in Fig. 1, for example, represents the following numbers and their sum: 1 2 3 4 5 2 3 4 5 6 3 4 5 6 7 4 5 6 7 8 5 6 7 8 9 6 7 8 9 0 7 8 9 0 1 8 9 0 1 2 9 0 12 3 Saunderson could carry out calculations with incredible rapidity using this machine. He also used it for representing geometrical figures, as in Fig. 2, employing either small-headed pins or threads to link together the large-headed pins that formed the vertices of his figures.]'® He was the author of a very perfect book of its kind, the Elements of Algebra, in which the only clue to his blindness is the occasional eccentricity of his demonstrations, which would perhaps not have been thought up by a sighted person. Tо him belongs the division of the cube into six equal pyramids having their vertices at the centre of the cube and the six faces as their bases; this is used for an elegant proof that a pyramid is one-third of a prism having the same base and height. The section in square brackets is a paraphrase of Diderot's lengthy account. 42