PLEASURE, PAIN AND INTELLIGENCE 153 



pose that along with the group of motor actions approximately adapted 

 to seize prey at this distance, the diffused discharge is, on some occasion, 

 so distributed throughout the muscular system as to cause a slight for- 

 ward movement of the body. Success will occur instead of failure ; and 

 after success will immediately come certain pleasurable sensations with 

 an accompanying draught of nervous energy towards the organs employed 

 in eating, etc. That is to say, the lines of nervous communication 

 through which the diffused discharge happened in this case to pass, have 

 opened a new way to certain wide channels of escape; and, consequently, 

 they have suddenly become lines through which a large quantity of molecu- 

 lar motion is drawn, and lines which are so rendered more permeable 

 than before. On recurrence of the circumstances, these muscular move- 

 ments that were followed by success are likely to be repeated : what was 

 at first an accidental combination of motions will now be a combination 

 having considerable probability." 



Bain's view of learning is much like that of Spencer. 



We suppose movements spontaneously begun, and accidentally caus- 

 ing pleasure; we then assume that with the pleasure there will be an 

 increase of vital energy, in which increase the fortunate movements will 

 share, and thereby increase the pleasure. Or, on the other hand, we sup- 

 pose the spontaneous movements to give pain, and assume that, with the 

 pain, there will be a decrease of energy, extending to the movements that 

 cause the evil, and thereby providing a remedy. A few repetitions of the 

 fortuitous concurrence of pleasure and a certain movement, will lead to 

 the forging of an acquired connection, under the law of Retentiveness or 

 Contiguity, so that, at an after time, the pleasure or its idea shall evoke 

 the proper movement at once. 



The theories of Bain and Spencer are discussed in detail by 

 Baldwin, who, while differing from these writers in certain points 

 which need not here be dwelt upon, adopts essentially the same 

 view as regards the mechanism of reinforcement and inhibition. 

 With Bain and Spencer, Baldwin assumes that 



the pleasure resulting from the first accidentally adaptive movement, 

 issues in a heightened nervous discharge toward the organs which made 

 the movement, a discharge which finds its way to the same channels as 

 before, and so makes it likely that the same movement will be repeated, 

 the external conditions remaining the same Pleasure and 



