CONSTITUENTS OF MATTER 131 



is seen by anybody else who would commonly be said to 

 see the same flash. What I mean may perhaps be made 

 plainer by saying that if my body could remain in 

 exactly the same state in which it is, although my mind 

 had ceased to exist, precisely that object which I now see 

 when I see the flash would exist, although of course I 

 should not see it, since my seeing is mental. The prin- 

 cipal reasons which have led people to reject this view 

 have, I think, been two : first, that they did not ade- 

 quately distinguish between my seeing and what I see ; 

 secondly, that the causal dependence of what I see upon 

 my body has made people suppose that what I see can- 

 not be " outside " me. The first of these reasons need 

 not detain us, since the confusion only needs to be 

 pointed out in order to be obviated ; but the second 

 requires some discussion, since it can only be answered 

 by removing current misconceptions, on the one hand as 

 to the nature of space, and on the other, as to the mean- 

 ing of causal dependence. 



When people ask whether colours, for example, or 

 other secondary qualities are inside or outside the mind, 

 they seem to suppose that their meaning must be clear, 

 and that it ought to be possible to say yes or no without 

 any further discussion of the terms involved. In fact, 

 however, such terms as " inside " or " outside " are very 

 ambiguous. What is meant by asking whether this or 

 that is " in " the mind ? The mind is not like a bag or a pie ; 

 it does not occupy a certain region in space, or, if (in a sense) 

 it does, what is in that region is presumably part of the 

 brain, which would not be said to be in the mind. When 

 people say that sensible qualities are in the mind, they 

 do not mean " spatially contained in " in the sense in 

 which the blackbirds were in the pie. We might regard 

 the mind as an assemblage of particulars, namely, what 



