78 THE PHILOSOPHY OF BIOLOGY 



From the point of view, then, of energetic processes 

 these are the characters of life, using the term in the 

 general sense indicated above. 1 



Is there an absolute distinction between the organic 

 mechanism and the inorganic one ? Let us note, for 

 the first time, that the actual physico-chemical trans- 

 formations themselves, which we study in inorganic 

 matter, are identical with those which we study in the 

 organism. Molecules of carbon dioxide, water, nitrate, 

 sodium chloride, potassium chloride, phosphate, and 

 so on, are just the same in inert matter as in the 

 organism. Chemical transformations, such as the 

 hydrolysis of starch, the inversion of cane sugar, or 

 the splitting of a neutral fat, are certainly just the same 

 processes, whether we carry them out in the glass 

 vessels of the laboratory, or observe them to proceed 

 in the living tissues of the animal body. The same 

 molecular rearrangements, and the same transfers 

 of energy, occur in both series of events. This, however, 

 is not the material of a distinction : what we have to 

 find is, whether the direction of a group of physico- 

 chemical reactions is the same in the organism and in 

 a series of inorganic processes. 



Let us return to the Carnot cycle. This is a series 

 of operations which occur in an imaginary mechanism 

 in such a manner that the whole series can be easily 

 reversed. Heat is supplied to the imaginary engine, 

 which then performs work and yields up its heat to a 

 refrigerator. Work is then performed on the engine, 

 which thereupon takes heat from the refrigerator and 

 returns it to the source. The work done by the engine 

 in the direct cycle is equal to the work done on it in 



1 This is, of course, the argument of part of Chapter II. of Bergson's Creative 

 Evolution. The reader will not find the essential differences between plants 

 and animals stated so clearly anywhere else in biological literature. 



