uncertain of our materials.

Again. The psychologist speaks of the relation of mind and body. Some
psychologists incline to be parallelists, some are warm advocates of
interactionism. Now, any theory of the relation of mind to body must
depend on observation ultimately. If we had not direct experience of a
relation between the physical and the mental somewhere, no hypothesis
on the subject would ever have emerged.

But our experiences are not perfectly clear and unequivocal to us.
Their significance does not seem to be easily grasped. To comprehend
it one is forced to that reflective examination of experience which is
characteristic of the philosopher (Chapter IX).

Here it may again be said: Leave the matter to the meta-physician and
go on with your psychological work. I answer: The psychologist is not
in the same position as the botanist or the zoölogist. He is studying
mind in its relation to body. It cannot but be unsatisfactory to him
to leave that relation wholly vague; and, as a matter of fact, he
usually takes up with one theory or another. We have seen (section 36)
that he may easily adopt a theory that leads him to overlook the great
difference between physical phenomena and mental phenomena, and to
treat them as though they were the same. This one may do in spite of
all that introspection has to say about the gulf that separates them.

Psychology is, then, very properly classed among the philosophical
sciences. The psychologist is not sufficiently sure of his materials
to be able to dispense with reflective thought, in many parts of his
field. Some day there may come to be a consensus of opinion touching
fundamental facts, and the science may become more independent. A