LIFE AND MIND 



ii 



Nearly all the later biologists or biological phil- 

 osophers are as shy of the term " vital force," and 

 even of the word " vitality," as they are of the words 

 "soul," "spirit," "intelligence," when discussing 

 natural phenomena. To experimental science such 

 words have no meaning because the supposed reali- 

 ties for which they stand are quite beyond the reach 

 of scientific analysis. Ray Lankester, in his "Sci- 

 ence from an Easy Chair," following Huxley, com- 

 pares vitality with aquosity, and says that to have 

 recourse to a vital principle or force to explain a 

 living body is no better philosophy than to appeal to 

 a principle of aquosity to explain water. Of course 

 words are words, and they have such weight with us 

 that when we have got a name for a thing it is very 

 easy to persuade ourselves that the thing exists. The 

 terms "vitality," " vital force," have long been in use, 

 and it is not easy to convince one's self that they 

 stand for no reality. Certain it is that living and non- 

 living matter are sharply separated, though when re- 

 duced to their chemical constituents in the laboratory 

 they are found to be identical. The carbon, the hy- 

 drogen, the nitrogen, the oxygen, and the lime, sul- 

 phur, iron, etc., in a living body are in no way pecul- 

 iar, but are the same as these elements in the rocks 

 and the soil. We are all made of one stuff ; a man and 

 his dog are made of one stuff; an oak and a pine are 



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