THE INDIRECT JUSTIFICATION OF ENTELECHY 199 



mechanical principles as such, it may be mentioned at 

 this place. 



Maxwell imagines two boxes of different temperature, 

 communicating by a small hole, which may be closed and 

 opened as you please. Now, he says, let us assume that 

 there is a sort of " demon," who is able to move the door 

 of the hole at his pleasure, and who only opens it when 

 a molecule of great velocity is passing from the box A 

 to the box B, but in no other case, the temperature of 

 B being the higher one. The result of doing so will be, 

 that the temperature of B, in spite of being the higher 

 one, will be raised at the expense of the temperature of 

 A; and this contradicts the second principle of thermo- 

 dynamics. 



It seems to me that in Maxwell's fiction things stand 

 just as they did in our instance of the workman and the 

 bricks, where only an increase of diversity of distribution 

 was accomplished by the vital agent. Let us not forget 

 that " temperature " as such does not exist for Maxwell 

 from his mechanical point of view : molecules in motion 

 are his elements to be studied, each of them endowed 

 with a specific velocity. His " demon " deals with these 

 molecules as our workman with his bricks ; he does not 

 create diversities of velocity, he only increases the amount 

 of diversity in the distribution of differently moving 

 molecules. In this sense there is no contradiction in 

 Maxwell's statements to the general principle of the role 

 of diversities in general becoming ; there only is a contradic- 

 tion to the second principle of mere thermodynamics : 

 but " heat >: and " temperature 3: are nothing elemental to 

 the mechanical physicist. Of course, the empirical law 



