312 THE PHILOSOPHY OF BIOLOGY 



instinctive and intelligent animal, in that it is used as 

 food and converted into bodily energ}^, which can then be 

 utilised for any purpose that is contemplated. These 

 plant substances taken in by the animal as sources of 

 energy are broken down into excretory substances, which 

 are further broken down by the metabolic activity of 

 the fermentation and putrefaction bacteria, and be- 

 come the substances used as foods by the chlorophyllian 

 organisms. 



If the activities of man were only those of un- 

 directed or misapplied muscular movements (as indeed 

 most of his activities have so far been), then cosmic 

 energy would truly be dissipated after it had become 

 the energy of organisms. But does not all the history 

 of man point to his ever-increasing activity in the 

 conquest over nature, that is, the effort to hoard and 

 employ natural sources of energy, and to arrest its 

 tendency towards dissipation ? 



It must be admitted that the past history of human 

 civilisation has been almost entirely that of the irre- 

 sponsible exploitation of natural resources — for it has 

 been founded on the thoughtless and wasteful utilisa- 

 tion of energy which was made potential by the plant 

 and animal organisms of the past. Man, the hunter, 

 maintained himself and multiplied by the destruction 

 of other animals or plants, or by the mere collection 

 and utilisation of naturally occurring fruits and other 

 plant-substances. During historic times the bison and 

 other animals have almost become extinct owing to his 

 i-uthless activity, just as in our own days the whale, 

 sole, and turbot are disappearing before the activity 

 of the machine-aided fisherman. Industrial man has 

 been successful with his factories and railroads and 

 steamships, and his electrical power and transport, 

 only because he has been able to utilise the stores of 



