ATOMIC THEORY. 400 



is yet hidden in the future. Certain paths, which we shall 

 hereafter notice, seem opening in this direction and have 

 been zealously pursued. We live in an age of new methods, 

 as well as new facts ; and where the object is not in its nature 

 insuperable by human reason, we may venture to aspire, if 

 not to certain truth, at least to that degree of presumptive 

 proof which is proximate to it. 



In the foregoing outline of the earlier questions and 

 opinions as to the atomic constitution of matter, we have 

 refrained from naming those of the ancient philosophers to 

 whom we chiefly owe them, believing that we might thereby 

 convey a clearer view of their purport and success. It will 

 occur to others as to ourselves, that the history of human 

 knowledge is often more clouded than illustrated by the long 

 array of names and shades of opinion, which are made to 

 enter into it. In the personal narrative of these victories or 

 vagaries of human thought, the reader loses sight of the 

 questions which lie at the bottom of the whole, and fails of 

 discerning what has really been done or is still left undone. 

 We cannot, however, omit to name some of those who early 

 laboured on this subject, seeing the eminent place they hold 

 in the history of mankind. 



It was impossible, indeed, that such men as Pythagoras, 

 Plato, Aristotle, Democritus, Empedocles, and Epicurus 

 for these names stand on the list should live in a 

 world full of such strange problems, without being attracted 

 forcibly to them. The principle of numbers as pro- 

 pounded by Pythagoras, though extravagant in its mys- 

 tical applications, yet is in some sort an anticipation of 

 what now rests on a close induction of facts. Leucippus 

 has been vaguely recorded as the first who treated of the 

 atomical composition of matter. Democritus and Epicurus 

 are with more certainty reputed as the philosophers who gave 

 higher form and consistency to the theory ; including under 



