80 BIOLOGICAL LECTURES. 



not be contemporaneous with the act, but may come considerably 

 later, and the act itself and impulse thereto may not be in the 

 least pleasurable. Our parallelist, therefore, who thinks that 

 the neural counterpart of the pleasurable feeling stamps in the 

 connection, has to show how the nervous activities aroused 

 by nervous currents from the taste buds, due to the presence of 

 fish in the mouth, can find their way around to the cells con- 

 cerned in the transmission of certain stimuli which came from 

 the retina and went out ten seconds ago to the end plates on the 

 leg muscles, and how, having safely arrived there, they can pick 

 out just the right cells and confirm in them just the right struc- 

 ture, so that when next those currents come from the retina 

 they will be directed in the particular way which shall make 

 the fore leg claw the button. He has, then, further to explain 

 how the neural actions arising from the taste of meat, the feel- 

 ing of company, sexual activity, etc., all find their way to the 

 same place and all do the same work. If he answers this by 

 saying that the pleasurable element of the feelings is in all 

 cases identical, and that therefore its neural counterpart is 

 identical and acts identically, he has the still harder problem of 

 explaining how any one neural activity can thus set its seal on 

 all sorts of nervous structure anywhere in the nervous system, 

 first convincing us also of the truth of the unlikely proposition 

 that the neural activities corresponding to the taste of fish, 

 sight of other chicks, and sensations from sexual contact have 

 one identical element. A speculative psychologist might at- 

 tempt all this, but where is the neurologist who would dare ? 



Yet the problem is not about fine-drawn distinctions, nor 

 a matter for metaphysical speculation, but is a clear question 

 about facts, and facts ever recurring in animal life, and so impor- 

 tant in animal economy that they surely ought not to be hud- 

 dled out of sight. The taste of the meat, or the neural action 

 corresponding thereto, does somehow strengthen the association ; 

 but for such influence the animal would react the hundredth 

 time as he did the first ; by such influence education by experi- 

 ence is possible. The answer, " Feelings of pleasure are them- 

 selves true causes," leaves us with a mystery on our hands. 

 The other answer, " The neural counterparts of the pleasurable 



