144 SCIENTIFIC METHOD IN PHILOSOPHY 



matter of immediate experience, the sensible flux is 

 devoid of divisions, and is falsified by the dissections of 

 the intellect. Now I have no wish to argue that this 

 view is contrary to immediate experience : I wish only to 

 maintain that it is essentially incapable of being proved by 

 immediate experience. As we saw, there must be among 

 sense-data differences so slight as to be imperceptible : 

 the fact that sense-data are immediately given does not 

 mean that their differences also must be immediately 

 given (though they may be). Suppose, for example, a 

 coloured surface on which the colour changes gradually 

 so gradually that the difference of colour in two 

 very neighbouring portions is imperceptible, while the 

 difference between more widely separated portions is 

 quite noticeable. The effect produced, in such a case, 

 will be precisely that of " interpenetration," of transition 

 which is not a matter of discrete units. And since it 

 tends to be supposed that the colours, being immediate 

 data, must appear different if they are different, it seems 

 easily to follow that " interpenetration " must be the 

 ultimately right account. But this does not follow. 

 It is unconsciously assumed, as a premiss for a 

 reductio ad absurdum of the analytic view, that, if A and 

 B are immediate data, and A differs from B, then the 

 fact that they differ must also be an immediate datum. 

 It is difficult to say how this assumption arose, but I 

 think it is to be connected with the confusion between 

 " acquaintance " and " knowledge about." Acquaintance, 

 which is what we derive from sense, does not, theoretically 

 at least, imply even the smallest " knowledge about/' i.e. 

 it does not imply knowledge of any proposition concern- 

 ing the object with which we are acquainted. It is a 

 mistake to speak as if acquaintance had degrees : there 

 is merely acquaintance and non-acquaintance. When we 



