m.] IDEAL GENESIS OF MATTER 241 



in that of growth. But it is no longer then of the universe 

 in its totality that we must speak. 



Why should we speak of it? The universe is an as- 

 semblage of solar systems which we have every reason 

 to believe analogous to our own. No doubt they are not 

 absolutely independent of one another. Our sun radiates 

 heat and light beyond the farthest planet, and, on the 

 other hand, our entire solar system is moving in a definite 

 direction as if it were drawn. There is, then, a bond 

 between the worlds. But this bond may be regarded as 

 infinitely loose in comparison with the mutual dependence 

 which unites the parts of the same world among them- 

 selves; so that it is not artificially, for reasons of mere 

 convenience, that we isolate our solar system: nature 

 itself invites us to isolate it. As living beings, we depend 

 on the planet on which we are, and on the sun that pro- 

 vides for it, but on nothing else. As thinking beings, 

 we may apply the laws of our physics to our own world, 

 and extend them to each of the worlds taken separately; 

 but nothing tells us that they apply to the entire universe, 

 nor even that such an affirmation has any meaning; for 

 the universe is not made, but is being made continually. 

 It is growing, perhaps indefinitely, by the addition of new 

 worlds. 



Let us extend, then, to the whole of our solar system 

 the two most general laws of our science, the principle of 

 conservation of energy and that of its degradation — 

 limiting them, however, to this relatively closed system 

 and to other systems relatively closed. Let us see what 

 will follow. We must remark, first of all, that these two 

 principles have not the same metaphysical scope. The 

 first is a quantitative law, and consequently relative, 

 in part, to our methods of measurement. It says that, 

 in a system presumed to be closed, the total energy, that 



