33 POPULAR SCIENCE MONTHLY. 



the divinity of whom they declare themselves a priori the organs, and 

 while they assume to impose them, even by force, as the eternal rules 

 of private and social life, men of science, having recognized the rela- 

 tive and historical source of these assertions, limit themselves to apply- 

 ing actual rules to the practical conduct of life, in morals and politics 

 as well as in hygiene and industry rules always provisional, and 

 subject to modification from day to day by the evolution of future 

 ages, as they have been constantly modified in past ages. 



The prime characteristic of modern science is its readiness to 

 declare the increasing uncertainty of its ideal constructions. While 

 it does not refuse to examine problems of origin, while it itself 

 furnishes the only probable data by the aid of which the solution of 

 them can be pursued, it affirms nothing and promises nothing in the 

 matter. It would consider it equally rash to set up on similar con- 

 structions the rules of industrial applications and moral rules for 

 the conduct of individuals and societies. In real things we never 

 proceed in the name of absolute principles, because we have learned 

 that all our principles rest upon hypotheses borrowed from the facts of 

 observation under a direct or simulated form. To deduce every- 

 thing from absolute principles is an illusion. Whatever pretends 

 to be supported on the absolute is supported on nothing. 



Man's knowledge is gained solely by the method of the observa- 

 tion of facts, but is derived from two sources, an internal and an 

 external one. Sensation reveals the external world to us, and is the 

 point of departure of all the physical, natural, and historical sciences. 

 It exhibits the insignificance and subordination of the individual in 

 mankind, present and past; the insignificance and subordination of 

 mankind overwhelmed and almost reduced to nothing in the infinite 

 whole of the universe. From this point of view, all morals con- 

 sist in our humble submission to the necessary laws of the world; 

 religions say nothing more than this when they subordinate the 

 human mind to the divine will. In this domain everything is ob- 

 jective. 



In the inner world, that of consciousness, on the contrary, the 

 man appears alone; his mind, his feelings, become the measure of 

 things. These have no existence for us, except on the condition that 

 they are known, and therefore from that point of view they exist 

 only for our intelligence and in our intelligence. In this domain 

 all is subjective. Such is the contrast I do not say opposition 

 between the two sources of our knowledge. ISTow, these two sources, 

 internal and external, of our positive knowledge are equally, I 

 repeat, the two sources of our morals. 



Human morality, no more than science, does not recognize a divine 

 origin; it does not proceed from religions. Its rules are drawn from 



