58o THE POPULAR SCIENCE MONTHLY. 



are tte transitions of genius distinguished by their express defiance 

 of all that is habitual. 



This led to the erection of other laws to supply the gaps in expla- 

 nation left by the law of habit alone. No sensible man now considers 

 the habit-philosophy of Hartley, Priestley, and James Mill to be ade- 

 quate to its task. Professor Bain, reverting to Hume's standpoint, 

 supplements the law of Contiguity by that of Similarity, and, in a sub- 

 ordinate degree, by that of Contrast. All the materials of thought, 

 without conception, are in his psychology pushed or drawn before 

 the footlights of consciousness by the working of these laws and by 

 them alone. 



Mr. Hodgson, ablest of recent (if not of all) English philosophers, 

 supplements Bain's laws by an important principle, that of Interest. 



And every one before whose consciousness, when falling asleep, 

 trains of faces and other disconnected images are wont to pass, and 

 who, moreover, after his attention has once been called to the subject, 

 surprises vestiges of the same process at work during his waking hours, 

 in the form of a sort of meteoric shower of random images, visual or 

 verbal, which cross the main current of thought, but are so faint 

 that they ordinarily arrest no attention and are forthwith forgotten * 

 — every such person, I say, will plead for the admission of a prin- 

 ciple of spontaneity or accidental arousal, along with the principles 

 already mentioned. 



In the pages that follow I accept all these laws save that of con- 

 trast ; and that I do not reject, but simply ignore and disregard on 

 the present occasion. I try to show how they all may follow from 

 certain variations in a fundamental process of activity in the brain. 

 In particular I reduce Contiguous and Similar Associations to one, by 

 exhibiting their most pronounced forms as mere extremes of a common 

 mode. But the reader is requested to remember that in thus trying 

 to explain, by laws of matter, what ideas shall be presented to con- 

 sciousness at any moment, I expressly repudiate the pretension to 

 explain the form of consciousness itself. Consciousness, as I under- 

 stand it, is always in the midst of the present aware of the past as 

 that from which the present came ; and, out of the materials which 

 the present furnishes, she is always comparing one part with another, 

 to select that which most fits her ends. These peculiarities of con- 

 sciousness were referred to above, when it was spoken of as a "pre- 

 siding arbiter." I am wholly unable to picture this strange discrimi- 

 nating industry, this bringing of things together in order to keep them 

 apart, this setting of ends and choosing from equal possibilities, in 

 terms of any physical process whatever. The laws of association to 

 be treated of here might, for aught we can see, be true in a creature 

 wholly devoid of memory or comparison. Each of his ideas would 

 vanish in the act of awakening its successor ; his mind (if such it 

 * See Maury's classic work, " Le Sommeil et les Reves." 



