ion what religious people say or do, but not why they say or do
these things. A description of the states of mind of religious people,
such as is given by Professor James, is interesting enough, but it is
their causation that is of fundamental importance. And their causation
is only to be understood by associating them with other and more
fundamental processes. Within recent years psychology owes much of the
advance made to a closer study of the physiology of the nervous system,
and if genuine advance is to be made in our understanding of religious
phenomena we must adopt the same plan of investigation. We do not, for
example, understand the nature of demoniacal possession by a mere
collation of cases. It is only when we put them side by side with
similar cases that now come under the control of the physician, and
associate them with certain peculiar nervous conditions, and a
particular social environment, that we find ourselves within sight of a
rational explanation. Without adopting this plan we are in the position
of one trying to determine the nature of a locomotive in complete
ignorance of its internal mechanism. Yet this is precisely the position
of the professional exponent of religion. As a student the budding
divine has his head filled with historic creeds, and texts, and dogmas,
and doctrines, none of which can possibly tell him anything of the real
nature of religion. On the contrary, they act as so many obstacles to
his acquiring real knowledge in later life. And it is a striking fact
that while the professional astronomer, biologist, or physicist each
adds to our knowledge of the subject that falls within his respective
department, we owe little or nothing of our knowledge of the nature of
religion to the professional theologian.

To put the whole matter in a sentence, the study of religion must be
affiliated to the study of life as a whole. If possible, we must get at
the determining factors that lead one person to expend his energy on
religion and see supernatural influence in a thousand and one details of
his life, while another person, with apparently the same mental
qualities, finds complete satisfaction in another direction, and is
conscious of no such supernatural influence. It is scientifically
inadmissible to posit a "religious faculty" organically ear-marked for
religious use. Something of this kind is evidently in the minds of those
who explain Darwin's agnosticism as due to atrophy of his religio