348 LAUGEL'S PROBLEMS OF NATUKE AND LIFE. 



though clouded by some terms of Greek philosophy, is 

 as good as any that have succeeded it. The well- 

 known definition of Bichat, ' La vie est 1'erisemble des 

 fonctions qui resistent a la mort,' and that of the En- 

 cyclopedic, ' La vie est le contraire de la mort,' are too 

 epigrammatically negative to be of any use. They 

 omit, too, that which is the very essence of all life, 

 viz., the faculty of reproducing life, more or less like 

 in kind to itself. No definition can be good which 

 does not include the condition of an organisation ca- 

 pable by sexual or other means of such reproduction. 



We think, too, that Time should be admitted as 

 one element in the definition sought for. Every form 

 of life, endlessly dissimilar though these be, has its 

 average period and limit of existence, as well as a 

 certain defined chronometry of all its functions. 

 Growth, maturity, final decay, and death belong to 

 living organisation in its every shape on earth. 



An eminent philosopher of our own time describes 

 life as ' consisting in the continuous adjustment of 

 internal relations to external relations ' a definition 

 which loses value in its generality. A power of adjust- 

 ment, indeed, brings us close to that conception of a 

 vital principle, which we have just noticed as one of 

 the vexed questions of physiology. We alluded to it 

 cursorily when speaking of the vital forces, but must 

 add a few words here, to denote more explicitly what 

 we think to be the true conclusion on the matter. We 

 cannot assert on actual proof that life is engendered 

 by, or engenders, any power or force peculiar to itself. 

 Nevertheless in recognising, which we must do, that 



