[UNION OF MIND AND BODY.]
But what now of the mysterious union of the two great ultimate facts of human experience? What should the followers of Newton and Locke say to this crowning instance of deep and awful mystery? Only one answer can be given. Accept the union, and generalise it. Find out the fewest number of simple laws, such as will express all the phenomena of this conjoint life. Resolve into the highest possible generalities the connections of pleasure and pain, with all the physical stimulants of the senses—food, tastes, odours, sounds, lights—with all the play of feature and of gesture, and all the resulting movements and bodily changes; and when you have done that, you have so far truly, fully, finally explained the union of body and mind. Extend your generalities to the course of the thoughts; determine what physical changes accompany the memory, the reason, the imagination, and express those changes in the most general, comprehensive laws, and you have explained the how and the why brain causes thought, and thought works in brain. There is no other explanation needful, no other competent, no other that would be explanation. Instead of our being “unfortunate,” as is sometimes said, in not being able to know the essence of either matter or mind—in not comprehending their union; our misfortune would be to have to know anything different from what we do or may know. If there be still much mystery attaching to this linking of the two extreme facts of our experience, it is simply this: that we have made so little way in ascertaining what in one goes with what in the other. We know a good deal about the feelings and their alliances, some of which are open and palpable to all mankind; and we have obtained some important generalities in these alliances. Of the connections of thought with physical changes we know very little: these connections, therefore, are truly and properly mysterious; but they are not intrinsically or hopelessly so. The advancing study of the physical organs, on the one hand, and of the mental functions, on the other, may gradually abate this mystery. And if a day arrive when the links that unite our intellectual workings with the workings of the nervous system and the other bodily organs shall be fully ascertained and adequately generalised, no one thoroughly educated in the scientific spirit of the last two centuries will call the union of mind and body any longer inscrutable or mysterious.
[Footnote 4: Fortnightly Review, October, 1868.]