THE FORCE BEHIND NATURE. 621 



Let us take, again, the simple case of magnetic attraction. A man 

 who knows nothing of magnetism sees a piece of iron, brought within 

 a certain distance of what looks looks like a horseshoe bar of the same 

 metal, suddenly jump toward its approximated ends ; and might, as 

 before, correctly express the fact in " terms of motion." But let him 

 take the piece of iron in his hands, so as to feel the " pull " upon it when 

 brought sufficiently near the magnet, and he then becomes conscious, 

 through his force-sense, of a poioer of which he was before utterly 

 ignorant. 



Thus, as it seems to me, an analysis of those psychical experiences 

 on which all our cognitions of the physical universe around us are 

 really based irresistibly lands us in the conclusion that, as Herbert 

 Spencer expresses it, " All the sensations through which the external 

 world is known to us are explicable by us only as resulting from 

 certain forms of force " ; the direct derivation of our conception of 

 force from our own experience of muscular tension (or, as I should 

 myself say, from our own sense of effort) being "a fact which no 

 metaphysical quibbling can set aside." In the words of the able 

 American writer I have already quoted, *' The conception of force is 

 one of those universal ideas which belong of necessity to the intellec- 

 tual furniture of every human mind." By no one has the principle for 

 which I am contending, been more clearly and more authoritatively 

 expressed than by Sir John Herschel, a philosopher who united to his 

 wonderful grasp of Nature-phenomena a profound insight into the 

 action of the mind of man in the interpretation of them : 



Whatever attempts have been made by metaphysical writers to reason away 

 the connection of cause and effect, and fritter it down into the unsatisfactory 

 relation of habitual [unconditional] sequence, it is certain that the conception of 

 some more real and intimate connection is quite as strongly impressed upon the 

 human mind as that of the existence of an external world, the vindication of 

 whose reality has, strange to say, been regarded as an achievement of no common 

 merit in the annals of this branch of philosophy. It is our own immediate con- 

 sciousness of effort^ when we exert force to put matter in motion or to oppose 

 and neutralize force, which gives us this internal conviction of power and causa- 

 tion, so far as it relates to the material world. — (Treatise on " Astronomy " in 

 Lardner's " Cyclopaedia," p. 232.) 



Man's position as the " interpreter of Nature " may be not inaptly 

 likened (as it seems to me) to that of an intelligent observer of the 

 working of a cotton -factory, with whose mechanical arrangements he 

 is entirely unacquainted, and of whose moving power he knows no- 

 thing whatever. He is taken into a vast apartment,* in which he is at 

 first utterly bewildered by the number and variety of the movements 

 going on around him ; but, by directing his attention to the several 



* In one of the flax-spinning mills belonging to the Marshalls, of Leeds, the whole of 

 the work is done on one floor, covering, I believe, two acres of ground, instead of in 

 the usual buildins; of several stories. 



