256 CREATIVE EVOLUTION 



must at least soften its outlines. The law of the con 

 servation of energy cannot here express the objective 

 permanence of a certain quantity of a certain thing, 

 but rather the necessity for every change that is brought 

 about to be counterbalanced in some way by a change 

 in an opposite direction. That is to say, even if it 

 governs the whole of our solar system, the law of the 

 conservation of energy is concerned with the relation 

 ship of a fragment of this world to another fragment 

 rather than with the nature of the whole. 



It is otherwise with the second principle of thermo 

 dynamics. The law of the degradation of energy 

 does not bear essentially on magnitudes. No doubt 

 the first idea of it arose, in the thought of Carnot, 

 out of certain quantitative considerations on the yield 

 of thermic machines. Unquestionably, too, the terms 

 in which Clausius generalized it were mathematical, 

 and a calculable magnitude, &quot;entropy,&quot; was, in fact, 

 the final conception to which he was led. Such pre 

 cision is necessary for practical applications. But the 

 law might have been vaguely conceived, and, if 

 absolutely necessary, it might have been roughly 

 formulated, even though no one had ever thought 

 of measuring the different energies of the physical 

 world, even though the concept of energy had not 

 been created. Essentially, it expresses the fact that 

 all physical changes have a tendency to be degraded 

 into heat, and that heat tends to be distributed among 



O 



bodies in a uniform manner. In this less precise 

 form, it becomes independent of any convention ; it 

 is the most metaphysical of the laws of physics, 

 since it points out without interposed symbols, without 

 artificial devices of measurement, the direction in 

 which the world is going. It tells us that changes that 



