time: the refreshing river 



known too many victories in the past to fall a prey now to the pessim- 

 ism of Mephistopheles. 



It would be quite erroneous to say, therefore, that because thermo- 

 dynamic order and biological organisation are two quite different 

 things, there is any conflict between them. Only as the time-process 

 goes on, only as the cosmic mixing proceeds, only as the temperature 

 of the world cools; do the higher forms of aggregation, the higher 

 patterns and levels of organisation, become possible and stable. The 

 probability of their occurrence increases. The law of evolution is a 

 kind of converse of the second law of thermodynamics, equally 

 irreversible but contrary in tendency. We are reminded of the two 

 components of Empedocles' world, ^tAta, friendship, union, 

 attraction; and velKos, strife, dispersion, repulsion. 



There remain one or two final points. First, we have not answered 

 the question why a metabolic upkeep becomes necessary about the 

 level of the beginnings of life. Basal metabolism, as it is called, that 

 continuous slow rate of combustion which goes on all the time when 

 the living organism is as much at rest as it can possibly be, is classically 

 described as the energy turnover required to "keep the organism in 

 being as a physical system," to maintain separation of phases, do 

 work at membranes, etc., etc. It is fair to say that basal metabolism 

 only appears slowly as we ascend the taxonomic scale. We hardly 

 know as yet whether it is a concept which can be applied to bacteria, 

 and there is much evidence that some forms of life, such as viruses, 

 bacterial spores, and even some animal eggs, can remain for long 

 periods of time in an inert state, consuming none of their stores and 

 apparently as much without metabolism as any crystal. Presumably 

 the higher living patterns do demand a good deal of additional energy 

 to keep them going. 



Secondly, there is the question of measurement. The nature of 

 holistic organisation is certainly not susceptible of the same kind of 

 measurement as thermodynamic mixed-up-ness, but we have no 

 reason whatever for supposing that its measurement is impossible. 

 When such a measurement has been achieved, it would be feasible 

 to apply it also to human social evolution. I see no reason for doubting 

 the possibility of this. 



Thermodynamics and Social Evolution. 



Mention of social evolution brings up a few reflections which in- 

 escapably present themselves. If the general principles here enunciated 



230 



