106 G. F. Becker — Kant as a Natural Philosopher. 



of rotation by tidal action, and inferred the former more rapid 

 rotation of the moon, I do not find in his papers a definite 

 statement as to the means by which the dissipation of orbitaL 

 energy is achieved. He did not regard planetary space as a 

 perfect vacuum and may have relied upon the resistance of the 

 interplanetary medium for the predicted effect. The fall of 

 such great and numerous masses as the planets into the sun 

 would, he says, immeasurably increase the heat of the central 

 body. He also seems to have regarded the planets of small 

 density as capable of combustion. The heat thus generated he 

 believed great enough to dissociate the material of the system 

 and to restore it to its original nebulosity.* Then commences 

 a fresh cycle of evolution. 



Kant's doctrine of the restoration of the nebula by the dis- 

 sociation attending the collapse of the solar system must cer- 

 tainly be pronounced false in the light of the second law of 

 thermodynamics. It is almost impossible, however, to see how 

 Kant could have avoided this error before Carnot's day. His 

 attempt was to frame a theory for the universe, for all time, 

 and some regenerative principle was a necessity to such a 

 scheme. The second law of thermodynamics as now under- 

 stood seems to divide everlasting time into two portions, the 

 former of which is a perfect blank. In the light of present 

 knowledge it would appear that the entire stellar system, 

 planets and residual nebulae alike, must have been in the con- 

 dition of an immensely diffused nebula not more than a few 

 hundred million years ago and that the universe is now hasten- 

 ing towards eternal death. It is evident that the initial diffu- 

 sion, whatever its date and its degree, can have lasted but an 

 instant, during which the potentialized molar energy repre- 

 sented the maximum proportion of the total energy of the 

 universe. By the principle of dissipation, molar energy is 

 continually wasting away or undergoing conversion into 

 molecular energy. Hence if the quantity of matter and the 

 total energy of the entire system are constant, the molar 

 energy at a period preceding that instant must have been 

 smaller and must then have increased. The only alternative 

 compatible with the second law seems to be to suppose that 

 the total energy of the universe underwent an increase at that 

 time. The universe would then not be a conservative system, 

 the equation of energy would not apply to it, and aliquid ex 

 nihilo fit. Such an increase of energy might or might not be 

 due to a creation of matter. Thus if the molar energy was 

 maximum within a finite period, either the quantity of energy 

 in the universe is variable and has been increased or there is 

 an undiscovered, regenerative, third law of thermodynamics 



* Kant's Werke, vol. i, p. 302. 



