310 RECENT PROGRESS OF THE THEORY OF VISION. 



violin-player with his finger, so exactly that its vibration 

 shall not be out by a hundredth part. 



Moreover, it is clearly possible, by using these sensible 

 images of memory instead of words, to produce the same 

 kind of combination which, when expressed in words, 

 would be called a proposition or a conclusion. For 

 example, I may know that a certain person with whose 

 face I am familiar, has a peculiar voice, of which I have 

 an equally lively recollection. I should be able with 

 the utmost certainty to recognise his face and his voice 

 among a thousand, and each would recall the other. But 

 I cannot express this fact in words, unless I am able to 

 add some other characters of the person in question 

 which can be better denned. Then I should be able to 

 resort to a syllogism and say, ' This voice which I now 

 hear belongs to the man whom I saw then and there.' 

 But universal, as well as particular conclusions, may be 

 expressed in terms of sensible impressions, instead of 

 words. To prove this I need only refer to the effect of 

 works of art. The statue of a god would not be 

 capable of conveying a notion of a definite character and 

 disposition, if I did not know that the form of face and 

 the expression it wears have usually or constantly a cer- 

 tain definite signification. And, to keep in the domain 

 of the perceptions of the senses, if I know that a par- 

 ticular way of looking, for which I have learnt how to 

 employ exactly the right kind of innervation, is necessary 

 in order to bring into direct vision a point two feet off 

 and so many feet to the right, this also is a universal 

 proposition which applies to every case in which I have 

 fixed a given point at that distance before, or may do so 

 hereafter. It is a piece of knowledge which cannot be 

 expressed in words, but is the result which sums up my 

 previous successful experience. It may at any moment 

 become the major premiss of a syllogism, whenever, in 

 fact, I fix a point in the supposed position and feel that I 



