572 HISTORY OF PHILOSOPHY. 



receive the aspirations of the divine reason. He gave great authority 

 to the evidence of common sense. "For," said he, "the judgments 

 on which all men agree bear strong internal testimony of truth. 

 The ray which enlightens them all at once is but an emanation of the 

 divine reason spread through all thinking beings." 



Heraclitus denned virtue as the empire which men exercise over 

 their passions. His morality was a corollary of his principal theory, 

 from which he deduced this excellent maxim, " That human laws 

 derive their authority from that divine law which governs all at its 

 will, and holds all in subjection." 



Hippocrates has been by some supposed a disciple of Heraclitus. 

 The father of medicine deserves a high rank among philosophers; 

 in all the branches of medical science he set an admirable example of 

 the method in which all other sciences should be pursued. He collated 

 and compared the results of his own observation, and all others of 

 which he could obtain a knowledge, and taught that true research 

 consisted in associating reason with experience. His system is con- 

 tained in a few words : ** All rules must be drawn from practice, 

 not anterior reasoning, but from experience directed by reason. The 

 judgment is a sort of memory which collects and puts in order all the 

 impressions it has received from the senses ; for, before thought is 

 produced, the senses have experienced all that which furnishes it, 

 and through them are materials conveyed to the understanding." 



However, all the philosophers of the school of Elea did not follow 

 this course of beginning with absolute rationality and ending in 

 doubt. 



Leucippus endeavoured to stop this war among the partisans of 

 reason and of experience, and he thus endeavoured to reconcile 

 their conflicting doctrines : " Experience shows us numerous and 

 distinct objects, motions and changes, productions and destructions; 

 reason seems to require unity, infinity, and permanence." Leucippus 

 distinguished the things composed from the elements of which 

 they were formed. These elements possessed a few peculiar pro- 

 perties, such as motion and form, were simple and indivisible, and 

 infinite in number. Thus the hypotheses of reason were satisfied; the 

 combinations of these particles were continually varying ; their 

 junction and separation caused the generation and dissolution of 

 things. Thus the senses were not outraged. This was the hypothesis 

 by which Leucippus considered he had solved the fundamental pro- 

 blem of the Eleatics. He did not differ much in his system from 

 those of his metaphysical predecessors; but Democritus advanced 

 still nearer to them. He pretended to prove the existence of those 

 atoms a priori by the aid of the principle "nothing comes of nothing." 

 He supposed that time had no beginning. " We cannot," says he, 

 "enquire why things exist, since they have always existed. We 

 can only enquire, what reasons we have for supposing that they exist 

 at all." His theory on sensations is curious, and is the first which is 

 to be met with in history. 



" The soul, the common principle of motion and thought, is material 

 and composed of atoms of fire. It is entirely passive in its intellectual 



