The Will. 757 



certainly, but autonomous. " It possesses more, he says, than is con- 

 tained in its antecedents. 



This sort of comparison will not do. We might as well try to com- 

 pare a ray of light with a pound of iron. It might do if the will were 

 an organ like a liver or a gizzard. But it is easy to prove that the will 

 is a mode of motion and not a thing. The admission that ' motives are 

 necessary antecedents of will " concedes that point, for while motives, 

 that is motions, are the necessary antecedents of motions, they are not 

 the antecedents of things. If, therefore, muscle moving, a mode of 

 mechanical motion, depends upon previous mechanical motion, and if 

 what it depends on is the will, it follows that the will is mechanical mo- 

 tion. If we look for the motives which go to make up the will, we find 

 them to be derived from unmistakable modes of mechanical motion in 

 the environment, as light, sound, touch, &c. , which give immediate rise 

 to afferent nervous currents. We have no warrant to justify a supposi- 

 tion that the intermediate terms of action whatever they are, which lie 

 between these initial forms of molecular motion, and final forms of the 

 same sort of molecular motion, are anything else than equivalent forms 

 of motion. If we should allow a stream of pure water to flow into a 

 barrel by the bung-hole, and then upon tapping it at the spigot should 

 get nothing but molasses, we would have a right to conclude that some 

 internal works transformed water into molasses ; but if we should get 

 nothing but pure water by the spigot we should not conclude that the 

 water was turned into molasses upon entering the barrel and turned 

 back into water again upon leaving it. 



Neither have we any reason or right to suppose that the molecular 

 motion which we plainly trace to its entrance into the brain case is there- 

 upon lost from the domain of physics. If we never saw any motor ex- 

 pression come from it, we would say it was dissipated as heat, which is 

 still, however, a form of molecular motion. Such a result happens 

 when we speak to a man in a sound sleep and get no answer. But when 

 we find a motor nervous current coming out of the skull, which is evi- 

 dently a sequel to one we detected going into it and is its physical coun- 

 terpart, we conclude that these two are connected by currents just like 

 them or their equivalents. If a boy dodges a snowball, it is because he 

 sees it, or at any rate if he did not see it he would not dodge it. There 

 is no reason to suppose that the sight stimulus which is a form of phy- 

 sical energy mingles with an immaterial stimulus or stimulates an ' 'im- 

 material substance," whatever that is, and that the subsequent physical 

 stimulation which goes down the efferent nerve and causes a "ducking" 

 of the head, is got by the reconversion of the force of this immaterial 

 substance into physical energy. We know there must be physical energy 

 in some form all the way through. Every force is made up by the com- 



