before he again goes forth into the wilderness of reality, to take
rest and refreshment in the oasis with which the Fata Morgana illudes
him; or as well might a prisoner hope to escape from his prison
through a door reflected in a mirror.

So much for the physiologist in his capacity of pure physicist. As
long as he remains behind the scenes in painful exploration of the
details of the machinery--as long as he only observes the action of
the players from behind the stage--so long will he miss the spirit of
the performance, which is, nevertheless, caught easily by one who
sees it from the front. May he not, then, for once in a way, be
allowed to change his standpoint? True, he came not to see the
representation of an imaginary world; he is in search of the actual;
but surely it must help him to a comprehension of the dramatic
apparatus itself, and of the manner in which it is worked, if he were
to view its action from in front as well as from behind, or at least
allow himself to hear what sober-minded spectators can tell him upon
the subject.

There can be no question as to the answer; and hence it comes that
psychology is such an indispensable help to physiology, whose fault
it only in small part is that she has hitherto made such little use
of this assistance; for psychology has been late in beginning to till
her fertile field with the plough of the inductive method, and it is
only from ground so tilled that fruits can spring which can be of
service to physiology.

If, then, the student of nervous physiology takes his stand between
the physicist and the psychologist, and if the first of these rightly
makes the unbroken causative continuity of all material processes an