THE UNIQUENESS OF THE INDIVIDUAL 



of the act of living, is shared unequally between August Weis- 

 mann^ and Alfred Russell Wallace. (Wallace''s views are known 

 to us only from a casual letter preserved by Edward Poulton.^ 

 They are about the same as Weismann''s, though less confid- 

 ently and much less lengthily expressed.) But before I try to 

 give an account of Weismann''s views, we must have a few 

 definitions; for the trouble with ""natural death' is not that it 

 lacks a meaning, but that it has the embarrassment of two or 

 three. By ""accidental death*', then, or simply '"death"', is meant 

 death from any cause whatsoever. *"Natural death** is that sort 

 of death by accident to which the age-specific decline of our 

 faculties, senescence^ has made a certain contribution, however 

 small. The contribution grows larger as we grow older: what 

 lays a young man up may lay his senior out: but it always falls 

 short of unity, for no one dies merely of the weight of years. 

 The greatest clinical pathologist of the last generation' looked 

 back upon his life for evidence of such a case. He once thought 

 he had found it in a colleague ninety-four years old, whose life 

 seemed merely to fade away; but autopsy showed a lobar 

 pneumonia of four days'* standing. 



We shall be obliged to use the term '"natural death"* in the 

 rather wide sense of the foregoing definition. Popular usage 

 quite rightly fines it down to forms of death to which senes- 

 cence has made a pretty big contribution, for it seems absurd 

 to say that a man of forty could die in part of old age. At all 

 events, what we are to discuss is not the event, death, but the 

 process of senescence. (The definition of death itself, in the 

 most familiar of its several meanings, can be valid only with 

 reference to some stated ""leveP of biological organization. A 

 society will die before its individual members, an individual 



^ The Duration of Life (pp. 1-66) and lAfe and Death (pp. 111-61); essays 

 reprinted in Weismann on Heredity^ ed. E. B. Poulton, S. Schonland, and 

 A. E. Shipley; 2nd ed., Oxford, 1891. 



2 The Duration of Life, pp. 23-4. » Cf. Lancet, 235, p. 87, 1938. 



18 



