PERCEPTION. 517 



assume different relative positions or configura- 

 tions. But of 7nindy our knowledge is more ex- 

 tensive and more precise; because we are con- 

 scious of its existence, and of many of its opera- 

 tions, which are comprised in the general term 

 thought. To assert that thought can be a pro- 

 perty of matter, is to extend the meaning of the 

 term matter to that with which we cannot per- 

 ceive it has any relation. All that we know of 

 matter has regard to space : nothing that we 

 know of the properties and affections of mind 

 has any relation whatsoever to space. 



A similar incongruity is contained in the pro- 

 position that thought is a Junction of the brain. 

 It is not the brain which thinks, any more than 

 it is the eye which sees ; though each of these 

 material organs is necessary for the production 

 of their respective effects. That which sees and 

 which thinks is exclusively the mind ; although 

 it is by the instrumentality of its bodily organs 

 that these changes take place. Attention to this 

 fundamental distinction, which, although obvious 

 when explicitly pointed out, is often lost sight 

 of in ordinary discourse, will furnish a key to 

 the solution of many questions relating to per- 

 ception, which have been considered as difficult 

 and embarrassing. 



The sensations derived from the different 

 senses have no resemblance to one another, and 

 have, indeed, no property in common, except 



