IV DESCARTES' DISCOURSE ON METHOD 175 



that it is single. Now squint, and sight tells you 

 that there are two marbles, while touch asserts 

 that there is only one. Next, return the eyes to 

 their natural position, and, having crossed the 

 forefinger and the middle finger, put the marble 

 between their tips. Then touch will declare that 

 there are two marbles, while sight says that there 

 is only one ; and touch claims our belief, when 

 we attend to it, just as imperatively as sight 

 does. 



But it may be said, the marble takes up a cer- 

 tain space which could not be occupied, at the 

 same time, by anything else. In other words, the 

 marble has the primary quality of matter, exten- 

 sion. Surely this quality must be in the thing, 

 and not in our minds ? But the reply must still 

 be ; whatever may, or may not, exist in the thing, 

 all that we can know of these qualities is a state 

 of consciousness. What we call extension is a 

 consciousness of a relation between two, or more, 

 affections of the sense of sight, or of touch. And 

 it is wholly inconceivable that what we call exten- 

 sion should exist independently of such conscious- 

 ness as our own. Whether, notwithstanding this 

 inconceivability, it does so exist, or not, is a point 

 on which I offer no opinion. Thus, whatever our 

 marble may be in itself, all that we can know of it 

 is under the shape of a bundle of our own con- 

 sciousnesses. 



Nor is our knowledge of anything we know or 



