THE METAPHYSICS OF SENSATION 269 



gcnce able to see, but devoid of the sense of touch, 

 could have no idea of a plane figure. Thus he 

 says in section 156: 



"All that is properly perceived by the visual faculty 

 amounts to no more than colours with their variations and 

 different proportions of light and*shade ; but the perpetual 

 mutability and fleetingness of those immediate objects of 

 sight render them incapable of being managed after the 

 manner of geometrical figures, nor is it in any degree useful 

 that they should. It is true there be divers of them per- 

 ceived at once, and more of some and less of others ; but 

 accurately to compute their magnitude, and assign precise 

 determinate proportions between things so variable and in- 

 constant, if we suppose it possible to be done, must yet be a 

 very trifling and insignificant labour." 



If, by this, Berkeley means that by vision alone, 

 a straight line cannot be distinguished from a 

 curved one, a circle from a square, a long line 

 from a short one, a large angle from a small one, 

 his position is surely absurd in itself and contra- 

 dictory to his own previously cited admissions; if 

 he only means, on the other hand, that his pure 

 spirit could not get very far on in his geometry, it 

 may be true or not; but it is in contradiction 

 with his previous assertion, that such a pure spirit 

 could never attain to know as much as the first 

 elements of plane geometry. 



Another source of confusion, which arises out 

 of Berkeley's insufficient exactness in the use of 

 language, is to be found in what he says about 

 solidity, in discussing Molyneux's problem, whether 



