Introductory and Historical 



main business of living things, which is to pass on in unbroken 

 continuity the never-dimmed fire of life itself.' 



Warthin (1929), whose insistence upon the fundamental 

 impossibility of modifying the tempo of human ageing, now or 

 at any time in the future, has an orgiastic tone quite out of 

 keeping with the rashness of such a prediction, writes: 



'We live but to create a new machine of a little later model 

 than our own, a new life-machine that in some ineffable way 

 can help along the great process of evolution of the species 

 somehow more efficiently than we could do were we immortal. 

 The Universe, by its very nature, demands mortality for the 

 individual if the life of the species is to attain immortality 

 through the ability to cope with the changing environment of 

 successive ages. ... It is evident that involution is a biologic 

 entity equally important with evolution in the broad scheme of 

 the immortal process of life. Its processes are as physiologic as 

 those of growth. It is therefore inherent in the cell itself, an 

 intrinsic, inherited quality of the germ plasm and no slur or 

 stigma of pathologic should be cast upon this process. What its 

 exact chemicophysical mechanism is will be known only when 

 we know the nature of the energy-charge and the energy-release of 

 the cell. We may say, therefore, that age, the major involution, 

 is due primarily to the gradually weakening energy-charge set in 

 action by the moment of fertilization, and is dependent upon 

 the potential fulfillment of function by the organism. The 

 immortality of the germ plasm rests upon the renewal of this 

 energy charge from generation to generation.' 



This passage is highly typical of the literature of old age to the 

 present day. There can be few branches of biology in which 

 uplifting generalization of this kind has so long been treated as 

 a respectable currency for scientific thought. 



In general, the more elaborate the attempts to depict 

 senescence in overall mathematical terms, the more intellec- 

 tually disastrous they have proved. One of the most celebrated 

 incursions of metaphysics into biology, that which postulates a 

 separate 'biological time', is best expounded in the words of 

 its sponsor, Lecomte du Noiiy (1936): 



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