time: the refreshing river 



A particularly neat example of the resolution of a dialectical con- 

 tradiction is that of nucleic acid synthesis by developing eggs. It was 

 first found that during the development of sea-urchin eggs, a large 

 quantity of histologically recognisable nuclein is formed for the 

 increasing number of nuclei. But it was then found that there was 

 no change whatever in the nuclein phosphorus or the nucleic acid 

 nitrogen during development. Here was a flat contradiction, but it was 

 resolved by workers who showed that there are two kinds of nucleic 

 acid, and that during development one of them, situated in the 

 cytoplasm, is transformed into the other kind situated in the new 

 nuclei. 



In the field of wider ideas, there is a convincing sense in which 

 one may say that the long-debated controversy between biological 

 mechanists and vitalists (much discussed in SB and GA) was a dialec- 

 tical deadlock which a judicious organicism has resolved.^ The 

 mechanists, enamoured of over-simplified physico-chemical explana- 

 tions of biological processes, which they regarded, quite rightly, as 

 heuristically valuable, maintained that all biological processes were 

 fully explicable in terms appropriate to the sciences of physics and 

 chemistry. The vitalists, always eager to safeguard objective com- 

 plexity (and at the same time to keep the world safe for animism), 

 maintained that vital phenomena would always escape physico- 

 chemical analysis. This deadlock, which in various forms had run 

 through the whole history of human thought, was overcome when it 

 was realised that every level of organisation has its own regularities and 

 principles, not reducible to those appropriate to lower levels of organi- 

 sation, nor applicable to higher levels, but at the same time in no way 

 inscrutable or immune from scientific analysis and comprehension. 

 Thus the rules which are followed in experimental morphology or 

 genetics are perfectly valid in their own right, but comprehension will 

 never be complete until what is going on at the other levels, both 

 above and below, is analysed and compared with the level in question.^ 

 Biological organisation is the basic problem of biology; it is not an 

 axiom from which biology must start. 



So in the same way, we may perhaps consider dialectical materialism 

 itself as the synthesis of the age-old contradiction between meta- 



^ This idea was put forward in a paper of mine in 1928, Quart. Rev. Biol., 3, 80. 



^ M. J. Adler {Dialectic, London, 1927, p. 164 ff.) suggests that the natural connection 

 between dialectical and organicistic thought is simply that entities in opposition are 

 likely to be parts (on one level) of which the whole, the synthesis, occupies the next 

 higher level. 



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