120 THE WORLD-ENERGY 



begun in thought, and is continuously guided "by thought. 

 And, after all, the supreme "experiment" is that which 

 thought performs upon itself, clarifying itself by self- 

 criticism, and thus making sure of its own consistency, of 

 its own harmony with the supreme law of thought which 

 law, let it be ever remembered, is also the central law of 

 all reality. This is the value of the universal logic 

 which, as Kant expresses it, is a "cathartic of the ordi- 

 nary understanding." 



To resume, then, Heraclitus is seen to have solved the 

 contradiction inherent in the doctrine of the Eleatic con- 

 ception of the world, by the discovery, substantially, that 

 quantity is not to be regarded as either continuous or 

 discrete; but that, rather, quantity is necessarily both 

 continuous and discrete that the discrete or measurable 

 is itself a necessary phase of the continuous, or measure- 

 less. And this discovery is also found to be distinctly 

 recognized as the discovery of the central truth of at least 

 all extended reality, by both Aristotle and Hegel. So 

 that, with them, motion, activity, becoming, constitutes 

 the central, vital truth of the world. 



And what is this but the doctrine of evolution in large 

 outline? Here, too, "all flows." There is no rest in the 

 sense of mere quiescence. Perpetual activity, perpetual 

 motion, characterizes the sum of all reality. 



At the same time, it seems well worth noticing, that 

 the first rigidly reasoned and, at least approximately, 

 consistent development of the doctrine of evolution 

 in modern thought, assumed a metaphysical character. 

 And this we owe to Spinoza, who presents the doctrine 

 under the form of a demonstration of the necessary 

 relation existing between substance and its modes 



