THE COMPOSITION OF MIND 



needed for the accurate description of the dif- 

 ference between the two cases. The objects 

 which the astronomer contemplates are simple 

 triangles, presenting simple relations of posi- 

 tion and magnitude ; while the objects contem- 

 plated by the naturalist are complex organisms, 

 presenting immensely compounded relations of 

 structure and function. Now, in speaking of 

 simple things or simple relations, such as lengths 

 and breadths, weights, times, and velocities, we 

 habitually predicate equality or inequality of 

 them. " Wherever the terms of the compari- 

 son, being both elementary, have only one as- 

 pect under which they can be regarded, and can 

 be specifically posited as either distinguishable 

 or indistinguishable, we call them either unequal 

 or equal. But when we pass to complex things, 

 exhibiting at once the attributes, size, form, col- 

 our, weight, texture, hardness, -— things which, 

 if equal in some particulars, are rarely equal in 

 all, and therefore rarelyindistinguishable, — then 

 we use the term like to express, partly the ap- 

 proximate equality of the several attributes sep- 

 arately considered, and partly the grouping of 

 them in a parallel manner in time and space. 

 Similarly with the relations involved in reason- 

 ing. If simple, they are recognized as equal ox 

 unequal; if complex, as like or unlike^ 



The essential difference, then, between the 

 quantitative reasoning employed in the most 



