Page:Principles of Psychology (1890) v1.djvu/254

234 PSTCHOLOOT. zestful than ever is the work, the work ; and fuller and deeper the import of common duties and of common goods. But what here strikes us so forcibly on the flagrant scale exists on every scale, down to the imperceptible transition from one hour's outlook to that of the next. Ex- perience is remoulding us every moment, and our mental reaction on every given thing is really a resultant of our experience of the whole world up to that date. The analo- gies of brain-physiology must again be appealed to to corroborate our view. Our earlier chapters have taught us to believe that, whilst we think, our brain changes, and that, like the auro- ra borealis, its whole internal equilibrium shifts with every pulse of change. The precise nature of the shifting at a given moment is a product of many factors. The acciden- tal state of local nutrition or blood-supply may be among them. But just as one of them certainly is the influence of outward objects on the sense-organs during the moment, so is another certainly the very special susceptibility in which the organ has been left at that moment by all it has gone through in the past. Every brain-state is partly determined by the nature of this entire past succession. Alter the latter in any. part, and the brain-state must be somewhat different. Each present brain-state is a record in which the eye of Omniscience might read all the fore- gone history of its owner. It is out of the question, then, that any total brain-state should identically recur. Some- thing like it may recur ; but to suppose it to recur would be equivalent to the absurd admission that all the states that had intervened between its two appearances had been pure nonentities, and that the organ after their passage was exactly as it was before. And (to consider shorter periods) just as, in the senses, an impression feels very dif- ferently according to what has preceded it ; as one color succeeding another is modified by the contrast, silence sounds delicious after noise, and a note, when the scale is sung up, sounds unlike itself when the scale is sung down ; as the presence of certain lines in a figure changes the ap- parent form of the other lines, and as in music the whole aesthetic effect comes from the manner in which one set of