Principles of western civilisation

54 WESTERN CIVILISATION CHAP.

which Natural Selection had worked. It was evident, however, as soon as attention became fixed upon the causes of variation in the types of life above the unicellular forms, that if the individuals amongst the higher forms of life had continued to be endowed with indefinite length of existence, in one important respect at least, progress would have been handicapped ; and that a vast series of results which we have come to associate with the later and higher processes of evolution could not have arisen. For with individuals occupying their places in nature indefinitely, there would have been no room for variation, adaptation, and progress, as we have come to witness these phenomena among the higher forms of life. Such forms must have been, other things being equal, in this respect at least, at a disadvantage in competition with forms represented by periodically recurring generations. The periodical death of the units was, in short, indicated as the necessary accompaniment of the advance which was being made. The individual must die to serve the larger interest of his kind in the immense process of progress upon which life had entered.

1 Tt may be seen at once, when the mind has mastered the subject, that the Weismann conception of the endowment of life with a fixed duration in the individual, as here discussed, is more essentially scientific, than any alternative theory of the limitation of life in the individual as due to mechanical causes, or to the molecular constitution of the cells. For against the latter theory, as mere conjecture, (rendered to some extent doubtful, from the fact that the length of the cycle of life in the individual is lengthened out or curtailed under our eyes, to serve the needs of the species), there must be set the certainty that, if forms of life (subject to infinitesimal variation) had been endowed with indefinite longevity, Natural Selection must in the long-run have eliminated them and have arrived at the phenomenon of a fixed duration in the individual as we now knowit. We are, in short, bound to accept the Weismann conception as a working hypothesis in preference to the other. If we adopt Herbert Spencer’s definition of life as ‘the continuous adjustment of internal relations to external relations” two things will be evident: (1) that the most

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