SIMPLE AND COMPOUND EVOLUTION. 315 



ception, indefinite but comprehensive, is always useful as an 

 introduction to a complete conception cannot, indeed, be 

 dispensed with. A complex idea is not communicable 

 directly, by giving one after another its component parts 

 in their finished forms; since if no outline pre-exists in 

 the mind of the recipient, these component parts will not 

 be rightly "combined. The intended combination can be 

 made only when the recipient has discovered for himself 

 how the components are to be arranged. Much labour has 

 to be gone through which would have been saved had a 

 general notion, however cloudy, been conveyed before the 

 distinct and detailed delineation was commenced. 



That which the reader has incidentally gathered respect- 

 ing the nature of Evolution from the foregoing sections, he 

 may thus advantageously use as a rude sketch, enabling him 

 to seize the relations among the several parts of the en- 

 larged picture as they are worked out before him. He will 

 constantly bear in mind that the total history of every sen- 

 sible existence is included in its Evolution and Dissolution; 

 which last process we leave for the present out of considera- 

 tion. He will remember that whatever aspect of it we are 

 for the moment considering, Evolution is always to be re- 

 garded as fundamentally an integration of Matter and dis- 

 sipation of Motion, which may be, and usually is, accom- 

 panied incidentally by other transformations of Matter and 

 Motion. And he \vill everywhere expect to find that the 

 primary re-distribution ends in forming aggregates which 

 are simple where it is rapid, but which become compound in 

 proportion as its slowness allows the effects of secondary 

 re-distributions to accumulate. 



106. There is much difficulty in tracing out trans- 

 formations so vast, so varied, and so intricate as those now 

 to be entered upon. Besides having to deal with concrete 

 phenomena of all orders, we have to deal with each group 

 of phenomena under several aspects, no one of which can be 



