

METHODS 5 



thing utterly unverifiable because the definition which they 

 kept was purely subjective. Once more, a definition of life 

 ought to separate living bodies from not-living bodies just 

 as chemists separate alcohols from aldehydes. Such a 

 result we obtain by limiting ourselves in our definition of 

 life to the study of the objective characters of living beings. 

 Now if we should accept a definition of life that can be ap- 

 plied to not-living bodies, the definition would be bad ; 

 it would not reach the end proposed ; it would be like a 

 definition of alcohols which could be applied to acetones. 



The complete objective study of life is possible by the 

 methods of the ordinary sciences of observation and ex- 

 periment ; and to this must be limited our enunciation of the 

 principle of continuity. It professes nothing more than 

 this between life and death the difference is of the same 

 order as that which exists between a phenol and a sulphate, 

 or between an electrified body and a neutral body. In 

 other words, all phenomena which we study objectively in 

 living beings can be analysed by the methods of physics and 

 chemistry. In other words, again, life is not freed from the ] 

 laws of universal mechanics. 



If men had limited themselves from the beginning to 

 objective methods of investigation, the question of the 

 principle of continuity would never even have been raised. 

 But an error of method has started up the problem and so it 

 is of use to call attention to the following point. Although we 

 define life by a sum total of characters, and consequently each 

 body that possesses this sum total of characters is to be called 

 living, other natural bodies without being living may also 

 possess one or even several of these characters. Thus we may 

 establish a classification of not-living bodies, in which we 

 place nearest to living bodies those which possess a great 

 number of characters in common with them (the enzymes, 



