8 LIFE: ITS NATUEE, OEIGIN AND MAINTENANCE 



doubtedly antithetical. Strictly and literally, the words animate and in- 

 animate express the presence or absence of ' soul ' ; and not in- 

 frequently we find the terms ' life ' and ' soul ' erroneously employed as if 



identical. But it is hardly necessary for me to state that 

 wtui soul the remarks I have to make regarding ' life ' must not 



be taken to apply to the conception to which the word 

 1 soul ' is attached. The fact that the formation of such a conception is 

 only possible in connection with life, and that the growth and elabora- 

 tion of the conception has only been possible as the result of the 

 most complex processes of life in the most complex of living 

 organisms, has doubtless led to a belief in the identity of life with 

 soul. But unless the use of the expression * soul ' is extended to a degree 

 which would deprive it of all special significance, the distinction between 

 these terms must be strictly maintained. For the problems of life are 



essentially problems of matter ; we cannot conceive of 

 problems of matter! ^* e * n ^e sc i entmc sense as existing apart from 



matter. The phenomena of life are investigated, and 

 can only be investigated, by the same methods as all other phenomena of 

 matter, and the general results of such investigations tend to show that 

 living beings are governed by laws identical with those which govern in- 

 animate matter. The more we study the manifestations of life the more 

 we become convinced of the truth of this statement and the less we are 

 disposed to call in the aid of a special and unknown form of energy to 

 explain those manifestations. 



The most obvious manifestation of life is ' spontaneous ' movement. 

 We see a man, a dog, a bird move, and we know that they are alive. We 



place a drop of pond water under the microscope, and 



see numberless particles rapidly moving within it ; we 

 ment. affirm that it swarms with ' life.' We notice a small 



mass of clear Hme changing its shape, throwing out 

 projections of its structureless substance, creeping from one part of the 

 field of the microscope to another. We recognise that the slime is living ; 

 we give it a name Amoeba Umax the slug amoeba. We observe similar 

 movements in individual cells of our own body ; in the white corpuscles of 

 our blood, in connective tissue cells, in growing nerve cells, in young cells 

 everywhere. We denote the similarity between these movements and 

 those of the amoeba by employing the descriptive term ' amoeboid ' for 

 both. We regard such movements as indicative of the possession of ' life ' ; 

 nothing seems more justifiable than such an inference. 



But physicists * show us movements of a precisely similar character in 

 substances which no one by any stretch of imagination can regard as 

 living ; movements of oil drops, of organic and inorganic mixtures, even of 

 mercury globules, which are indistinguishable in their character from 

 those of the living organisms we have been studying : movements which 

 * G. Quincke, Annal. d. Physik u. Chem., 1870 and 1888. 



