An Introduction to a Biology 



system and all it controls are the elaborate instrument of 

 the soul. I do not deny for a moment, therefore, that the 

 organism employs physical, chemical, and mechanical means 

 to carry out its work. But if you think that when you have 

 described these means you have interpreted life, it seems 

 to me that you are resting when your work has only just 

 begun. You have not explained why a baby sucks at its 

 mother's breast when you have described how it does so 

 in the terms of the village pump. 



If we confine ourselves to the chemical activities of the 

 organism we may compare, as Bergson compares, the 

 organism to a retort, and its various juices to the contents 

 of that retort. The retort corresponds to the essentially 

 vital part of the organism and the contents to the inorganic 

 substances in its composition. Doubtless, it would be dim- 

 cult to draw a hard-and-fast line and say where, within 

 the organism, retort ends and contents begin. But the 

 comparison is only intended to be a rough one and to draw 

 a general distinction, not a sharp line, between the essen- 

 tially living parts of the body to which chemical principles 

 do not apply ; and those parts, or rather contents, of the 

 organism which are not one with the most vital part of the 

 organism, i.e. its individuality (or soul), and which, like for 

 instance cartilage or chitin, or bone or pigment, are the 

 same over a long series of animals. These parts, whether 

 they constitute the scaffolding, like bone, or the clothing, 

 like pigment, we may regard as separable or detachable 

 elements in the body, which do not enter into any close 

 union with the essential life of the organism. With regard 

 to pigments, these constitute, as it were, the outermost, 

 the most non-living layer of the not living parts of the 

 organism. They are limited in number, like the paints on 

 the painter's palette ; though the variety of pictures which 

 the animal or plant can paint with them on its own wings or 

 petals is without end. It is the picture which it paints, the 

 type of its species, which is individual and unique and 

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