4 PRELIMINARY CONSIDERATIONS. 



employ his understanding most effectively. 1 It appears, there- 

 fore, right and proper to reject the narrowly individualistic 

 conception of human nature and human reason, which traces 

 the origin of leading methodological concepts to the superior 

 minds of a few distinguished thinkers, and to posit the liberat- 

 ing and the perfecting of the human intelligence through pan- 

 humanly developed methods of thought. Our great men, we 

 shall see, are first and foremost historic milestones; they con- 

 veniently, ably, and enthusiastically summarise for us the larger 

 and more definite results of an epoch in a specific direction. 



II. THE UNITY OF NATURE AND OF LIFE. 



2. The nineteenth century established in the minds of men 

 the concept of the uniformity of nature. No longer, therefore, 

 can it be asserted, without calling forth emphatic and almost 

 universal protest, that objects alter their nature indifferently, 

 or that there are countless occult forces whose activities make 

 reliance on experiment fatally precarious. 2 Men affirm now 

 boldly, and in the very act of affirming they lay the foundations 

 of science, that given a certain cause a certain effect will 

 invariably follow under certain defined natural conditions. 



It will be the privilege of the twentieth century to lodge in 

 the human mind the notion of the unity of nature. The concept 

 is yet far from having been generally assimilated. There are 

 not a few men who consider that action at a distance should 

 be assumed as a simple fact, and that it savours of metaphysics 

 to seek for the proto-element or stuff out of which the chemical 

 elements have possibly been formed. Others not only doubt 

 whether we shall ever know intimately the stellar regions or 

 the world of atoms, but they discern a break between non- 



1 See 73 for a historical analysis. 



' 2 "Pendant des siecles, les hommes ont cru que meme ies mineraux 

 n'etaient pas regis par des lois definies, mais pouvaient prendre toutes les 

 formes et toutes les proprietes possibles pourvu qu'une volonte suffisamment 

 puissante s'y appliquat. On croyait que certaines formules ou certains gestes 

 avaient la vertu de transformer un corps brut en un etre vivant, un homme 

 en un animal ou une plante, et inversement." (E. Durkheirn, in De la rne- 

 thode dans les sciences, 1910, p. 308.) 



"In the 17th century Alexander Ross, commenting on Sir Thomas Browne's 

 doubt as to whether mice may be bred by putrefaction, flays his antagonist 

 in the following words: 'So may we doubt whether in cheese and timber 

 worms are generated, or if beetles and wasps in cow-dung, or if butterflies, 

 locusts, shell-fish, snails, eels, and such like, be procreated of putrefied 

 matter, which is to receive the form of that creature to which it is by forma- 

 tive power disposed. To question this is to question reason, sense, and ex- 

 perience. If he doubts this, let him go to Egypt, and there he will find the 



