time: the refreshing river 



infringement of the second law on the part of Uving organisms has 

 ever been forthcoming, and on the contrary a great deal of evidence 

 that they obey it. Their life is always associated with, and depends 

 upon, the processes of metabolism, in which there is always a net 

 loss of free energy, complex organic compounds being broken down 

 to CO2 and water, and their energy being dispersed as irrecoverable 

 heat. The processes of metabolism, moreover, are invariably very 

 inefficient.^ 



The idea that living organisms might be cheats in the game of 

 entropy originated from the conception of the so-called Clerk- 

 Maxwell demon. Clerk-Maxwell, in his expositions of the second law, 

 found it convenient to picture a vessel divided into two compartments 

 which were connected by a hole and a trap-door which could be 

 opened and shut at will by a "being whose faculties are so sharpened 

 that he can follow every molecule in its course."^ The demon could 

 thus let through fast molecules but not slow ones, in which case, 

 starting from a uniform temperature, one side would get hot and 

 the other side cold. He could therefore easily, in Kelvin's words,^ 

 make water run uphill, one end of a poker red-hot and the other 

 ice-cold, and sea-water fit to drink. The idea has thus been often put 

 forward that living organisms evade the second law. "Es gibt seine 

 Damonen," cried Driesch,* "wir selbst sind sie." But as Clark^ 

 rightly says, what had really been proved was not that the second 

 law was inapplicable to living matter, but that, z/a mind could deal 

 with individual molecules, and if it had suitable frictionless apparatus 

 at its disposal, and if it was desirous of doing so at the moment when 

 an observer happened to be looking, it could decrease entropy. These 

 conditions are never, in practice, fulfilled. So far as- we know, living 

 organisms and their minds cannot handle molecules individually. 

 The Maxwellian demon had in fact been endowed in its definition 

 with just the qualities our minds possess of arranging, sorting and 

 ordering. And our minds do not exist "in a vacuum," created from 

 nothing; they belong to the highest stage in an evolutionary process 

 continuous back to the most primitive single living cells. But the 

 paradox is that in all this arranging, sorting and ordering which 



^ See J. Needham, "Recent Developments in tlie Philosophy of Biology," Quart. 

 Rev. Biol., 1928, 3, 77. 



^ J. Clerk-Maxwell, Theory of Heat (4th ed.), 1875, p. 328 ff. 



^ Kelvin, Proc. Roy. Inst., 1879, ^» ^^3- 



* Driesch, H., Science and Philosophy of the Organism (London, 19 12), vol. ii, 202. 



^ Clark, R. E. D., School Sci. Rev., 1940, 21, 11 25. 



216 



