LIFE: ITS NATURE, ORIGIN AND MAINTENANCE 



EVERYBODY knows, or thinks he knows, what life is ; at least, we are all 

 acquainted with its ordinary, obvious manifestations. It would, therefore, 



seem that it should not be difficult to find an exact 

 definition. The quest has nevertheless baffled the 

 most acute thinkers. Herbert Spencer devoted two chapters of his 

 ' Principles of Biology ' to the discussion of the attempts at definition 

 which had up to that date been proposed, and himself suggested another. 

 But at the end of it all he is constrained to admit that no expression had 

 been found which would embrace all the known manifestations of animate, 

 and at the same time exclude those of admittedly inanimate, objects. 



The ordinary dictionary definition of life is 'the state of living.' 

 Dastre, following Claude Bernard, defines it as ' the sum total of 

 the phenomena common to all living beings.' Both of these definitions 

 are, however, of the same character as Sidney Smith's definition of an 

 archdeacon as ' a person who performs archidiaconal functions.' I am 

 not myself proposing to take up your time by attempting to grapple with a 

 task which has proved too great for the intellectual giants of philosophy, 

 and I have the less disposition to do so because recent advances in 

 knowledge have suggested the probability that the dividing line between 

 animate and inanimate matter is less sharp than it has hitherto been 

 regarded, so that the difficulty of finding an inclusive definition is corre- 

 spondingly increased. 



As a mere word ' life ' is interesting in the fact that it is one of those 

 abstract 'terms which has no direct antithesis ; although probably most 

 persons would regard ' death ' in that light. A little consideration will show 

 that this is not the case. ' Death ' implies the pre-existence of ' life ' ; 

 there are physiological grounds for regarding death as a phenomenon of 

 life it is the completion, the last act of life. We cannot speak of a non- 

 living object a& possessing death in the sense that we speak of a living object 

 as possessing life. The adjective ' dead ' is, it is true, applied in a popular 

 sense antithetically to objects which have never possessed life ; as in the 

 proverbial expression ' as dead as a door-nail.' But in the strict sense 

 such application is not justifiable, since the use of the terms dead and 

 living implies either in the past or in the present the possession of the 

 recognised properties of living matter. On the other hand, the expressions 

 living and lifeless, animate and inanimate, furnish terms which are un- 



* La vie et la mort, English translation by W. J. Greenstreet, 1911, p. 54. 



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