654 ^^^ POPULAR SCIENCE MONTHLY. 



at full length before us." Lange speaks of Bacon's high appreciation 

 of Democritus — for ample illustrations of which I am indebted to my 

 excellent friend Mr. Spedding, the learned editor and biographer of 

 Bacon. It is evident, indeed, that Bacon considered Democritus to 

 be a man of weightier metal- than either Plato or Aristotle, though 

 their philosophy " was noised and celebrated in the schools, amid the 

 din and pomp of professors." It w^as not they, but Genseric and At- 

 tila and the barbarians, who destroyed the atomic philosophy. " For, 

 at a time when all human learning had suffered shipwreck, these 

 planks of Aristotelian and Platonic philosophy, as being of a lighter 

 and more inflated substance, were preserved and come down to us, 

 while things more solid sank and almost passed into oblivion." 



The principles enunciated by Democritus reveal his uncompromising 

 antagonism to those who deduced the phenomena of Nature from the 

 caprices of the gods. They are briefly these : 1. From nothing comes 

 nothing. Nothing that exists can be destroyed. All changes are due 

 to the combination and separation of molecules. 2. Nothing happens 

 by chance. Every occurrence has its cause from which it follows by 

 necessity. 3. The only existing things are the atoms and empty 

 space ; all else is mere opinion. 4. The atoms are infinite in number, 

 and infinitely various in form ; they strike together, and the lateral 

 motions and whirlings which thus arise are the beginnings of w^orlds. 

 5. The varieties of all things depend upon the varieties of their atoms, 

 in number, size, and aggregation. 6. The soul consists of free, smooth, 

 round atoms, like those of fire. These are the most mobile of all. They 

 interpenetrate the whole body, and in their motions the phenomena of 

 life arise. Thus the atoms of Democritus are individually without 

 sensation ; they combine in obedience to mechanical laws ; and not 

 only organic forms, but the phenomena of sensation and thought, are 

 also the result of their combination. 



That great enigma, " the exquisite adaptation of one part of an or- 

 ganism to another part, and to the conditions of life," more especially 

 the construction of the human body, Democritus made no attempt to 

 solve. Empedocles, a man of more fiery and poetic nature, introduced 

 the notion of love and hate among the atoms to account for their com- 

 bination and separation. Noticing this gap in the doctrine of De- 

 mocritus, he struck in w^ith the penetrating thought, linked, however, 

 with some wild speculation, that it lay in the very nature of those 

 combinations which were suited to their ends (in other words, in har- 

 mony with their environment) to maintain themselves, while unfit 

 combinations, having no proper habitat, must rapidly disappear. Thus 

 more than two thousand years ago the doctrine of the " survival of 

 the fittest," which in our day, not on the basis of vague conjecture, 

 but of positive knowledge, has been raised to such extraordinary sig- 

 nificance, had received at all events partial enunciation.^ 



» Lange, 2d edit., p. 23. 



