THE RELATION OF LIFE TO OTHER FORCES. 323 



one of the actions included in this term namely, mechanical movement 

 although one of the most striking, is by no means a distinctive one. 

 For it must be remembered that one of the commonest transformations of 

 physical force with which we are acquainted is that of heat into mechani- 

 cal motion, and that this may be effected by an apparatus having itself 

 nothing whatever to do with life. The peculiarity of the manifestation 

 in an animal or vegetable is that of the organ by which it is effected, and 

 the manner in which the transformation takes place, not in the ultimate 

 result. The mere fact of an animal's possessing capability of movement 

 is not more wonderful than the possession of a similar property by a steam 

 engine. In both cases alike, the motion is the correlative expression of 

 force latent in the food and fuel respectively; but in one case we can 

 trace the transformation in the arrangement of parts, in the other we 

 cannot. 



The consideration of the products of the transformation of force 

 effected by the nervous system would lead far beyond the limits of the 

 present chapter. But although the relation of mind to matter is so little 

 known that it is impossible to speak with any freedom concerning such 

 correlative expressions of physical force as thought and nerve-products^ 

 still it cannot be doubted that they are as much the results of transfer-' 

 mation of force as the mechanical motion caused by the contraction of a 

 muscle. But here the mystery reaches its climax. We neither know 

 how the change is effected, nor the nature of the product, nor its analo- 

 gies with other forces. It is therefore better, for the present, to confess 

 our ignorance, than, with the knowledge which we have lately gained, to 

 build up rash theories, serving only to cause that confusion which is 

 worse than error. 



It may be said, with perfect justice, that even if the foregoing conclu- 

 sions be accepted, namely, that all manifestations of force by living beings 

 are -correlative expressions of ordinary physical force, still the argument 

 is based on the assumption of the existence of the apparatus which we 

 call living organized matter, with power not only to use external force 

 for its own use in growth, development, and other vital manifestations, but 

 for that modification of these powers which consists in the separation of 

 a part that shall grow up into the likeness of its parent, and thus con- 

 tinue the race. We are therefore, it may added, as far as ever from any 

 explanation of the origin of life. This is of course quite true. The ob- 

 ject of the present chapter, however, is only to deal with the relations of 

 life, as it now exists, to other forces. The manner of creation of the 

 various kinds of organized matter, and the source of those qualities, 

 belonging to it, which from our ignorance we call inherent, are different 

 questions altogeth 



To say that of necessity the power to form living organized matter 

 will never be vouchsafed to us, that it is only a mere materialist who 



