ay 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.

FOOTNOTES:

[Footnote 4: _Fortnightly Review_, October, 1868.]

[Footnote 5: We may here recall an incident highly characteristic of the
late Earl of Carlisle. Being elected on one occasion to the office of
Lord Rector of Marischal College, Aberdeen, he had to deliver an address
to the students on the usual topics of diligence and hopefulness in
their studious career. Referring for a model to the addresses of former
rectors, he found, in that of his immediate predecessor, Lord Eglinton,
the Homeric sentiment above alluded to. It grated harshly on his mind,
and he