I30 ESSAYS IN PHILOSOPHY 



existence constantly new. The series of element- 

 combinations is not recurrent, and the world-whole 

 moves, not in a circuit, but in a continual advance. 

 This movement is carried forward by the Logic of 

 Nature, that is, by the combined action of causa- 

 tion, space, and time, which are its only ultimate 

 principles. Hence real causation is the transfer of 

 motion by the impact of extended parts, and the 

 evolution of the world proceeds by the single prin- 

 ciple of mechanism. Strictly, then, universal logic 

 is simply a Mechanics of Nature} This cosmic 

 principle unfolds itself, primarily, in two auxiliary 

 ones, — the Laiv of Difference and the Law of 

 Definite Nmnber. The logic of the universe, bear- 

 ing onward in obedience to these, must move, how- 

 ever, to a definite result, the above-named Final 

 Purpose of the World : this real logic must play 

 the form inherent in it out to completion. Thus 

 the universe moves to a self-predestined close^ and 

 is therefore under a third and final law, — the Law 

 of the Whole. 



These three laws, now, are the Open Sesame to 

 all philosophy, theoretical or practical. They are, 

 for instance, the secret of that Natural Dialectic 



1 Diihring's earliest book of mark was his Critical History of the 

 General Principles of Mechanics, a work crowned by the University 

 of Gottingen, and held, generally, in the highest esteem. It passed 

 to its second edition in 1877. ^ third edition has recently appeared. 



