6 An Appeal to the Young. 



persons; because social inequality, which divides 

 society into two classes — the wage-slaves and the 

 grabbers of capital — renders all its teachings as to 

 the conditions of a rational existence only the bitter- 

 est irony to nine-tenths of mankind. 



I could give plenty more examples, but I stop 

 short: only go outside Faust's closet, whose win- 

 dows, darkened by dust, scarce let the light of heaven 

 glimmer on its shelves full of books; look round, 

 and at each step you will find fresh proof in support 

 of this view. 



It is now no longer a question of accumulating 

 scientific truths and discoveries. We need above 

 everything to spread the truths already mastered by 

 science, to make them part of our daily life, to ren- 

 der them common property. We have to order 

 things so that all, so that the mass of mankind, may 

 be capable of understanding and applying them ; we 

 have to make science no longer a luxury, but the 

 foundation of every man's life. This is what justice 

 demands. 



I go further : I say that the interests of science 

 itself lie in the same direction. Science only makes 

 real progress when a new truth finds a soil already 

 prepared to receive it. The theory of the mechani- 

 cal origin of heat, though enunciated in the last cen- 

 tury in the same terms that Hirn and Clausius 

 formulate it to-day, remained for eighty years buried 

 in the Academical Records until such time as knowl- 

 edge of physics had spread widely enough to create 

 a public capable of accepting it. Three generations 

 had to go by before the ideas of Erasmus Darwin on 

 the variation of species could be favorably received 

 from his grandson and admitted by academical phi- 

 losophers, and not without pressure from public 

 opinion even then. The philosopher, like the poet 

 or artist, is always the product of the society in 

 which he moves and teaches. 



