816 RECENT PROGRESS OF THE THEORY OF VISION. 



verification extend, which is really as far as for practical 

 purposes we need. 



Beyond these limits, as, for example, in the region of 

 Qualities, we are in some instances able to prove con- 

 clusively that there is no correspondence at all between 

 sensations and their objects. 



Only the relations of time, of space, of equality, and 

 those which are derived from them, of number, size, 

 regularity of coexistence and of sequence — ' mathematical 

 relations' in short — are common to the outer 'and the 

 inner world, and here we may indeed look for a complete 

 correspondence between our conceptions and the objects 

 which excite them. 



But it seems to me that we should not quarrel with 

 the bounty of nature because the greatness, and also the 

 emptiness, of these abstract relations have been concealed 

 from us by the manifold brilliance of a system of signs ; 

 since thus they can be the more easily surveyed and used 

 for practical ends, while 5^et traces enough remain visible 

 to guide the philosophical spirit aright, in its search after 

 the meaning of sensible Images and Signs. 



