president's address — SECTION J. 255 



consciousness. Here the materialist may turn upon us. It is absurd, 

 he argues, to assert the contractiUty of muscle apart from muscle, or 

 digestion apart from its appropriate organ ; and we are entitled, in a 

 similar way, to regard mental action as a cerebral function, inseparable 

 from the brain- workings by which it is conditioned. It is doubtless 

 true that contractility is a mere name apart from that which contracts, 

 and that digestion is impossible apart from the organ which digests. 

 But the point is that while the investigation of muscle discloses its 

 contractility, and a knowledge of the stomach discloses its power of 

 digestion, no investigation of the brain as such will ever disclose a 

 single mental fact. Cerebral changes do not of themselves reveal 

 mind ; and, conversely, a child may be aware of his own thought and 

 feeling even though he knows nothing of the hemispheres or grey 

 matter of the brain. The analogy, therefore, breaks down, and is 

 seen to be onlv another of the ingenious but unsuccessful attempts 

 which have been so often made to confuse the boundaries of psychology 

 and physiology. 



Yet, it may be said, admitting the difference between mind and 

 matter, may it not be true that mind is the effect of matter ? May 

 not material changes be the causes of mental facts, even though they 

 be not equivalent ? This, I take it, is really the problem which troubles 

 the ordinary man. I have already admitted that nervous changes 

 condition mental facts. This, however, does not exclude the possi- 

 bility that mind may have something to do with our motor activities, 

 and especially with those that are deliberately willed. Most men are 

 ready to believe that, if anyone strikes against an obstacle, the sensa- 

 tion which he feels is the result of a physical stimulus imparted to the 

 nervous system, and, on the other hand, that the removal of the obstacle 

 may be conditioned by the will to remove it. But the thorough-going 

 materialist believes in a one-sided activity, in which causation proceeds 

 wholly from matter. Consciousness in its varied forms is on this view 

 determined by bodily change ; but consciousness does not exert the 

 slightest influence on our bodily activities. How, he asks, can mind 

 alter the direction of motion, or change the position of molecules in 

 the brain ? Perhape we may be unable to answer this question. But 

 if we cannot explain how mind influences matter, neither can the 

 materialist tell us how matter can originate or influence any mental 

 change. Yet he has no doubt of the causal action of the body in 

 producing mental facts, while he scorns the supposition that mind can 

 influence nervous change even to the slightest extent. He appeals 

 again to the doctrine of the conservation of energy, which, as we have 

 seen, is applicable only to the material world. The energy of the 

 material imiverse is believed to be constant in its amount. If so, the 

 mind is powerless either to create or to annihilate energy. And if it 

 be suggested that, in some unknown way, the mind may to some extent 

 alter the direction of energy without increasing or diminishing its 

 amount, this is emphatically denied. The material world is thus 

 represented as a closed circle, impervious to psychical guidance or 

 control. But the argument cuts both ways. If, from moment to 



