all agreeing in their symptom, and differing
only in the explanation offered. The series would commence with the
explanation of a possessing spirit, and end with that of a deranged
nervous system. Ignorant of the nature, or even of the existence, of a
nervous system, primitive man explains abnormal mental states as due to
a malignant spirit. Martin Luther, George Fox, or John Bunyan, living at
a time when the activity of evil spirits was a firmly held doctrine,
attribute their infirmities to satanic influence. We are in the true
line of descent. To-day we have with us every one of the phenomena on
which the satanic theory rested, but they are described, and prescribed
for, in medical works instead of manuals of exorcism. The
supernaturalist theory gives way to that of the expert neurologist. The
exorcist is replaced by the physician. Instead of expelling an intruding
demon, we have to repair a deranged system. We cannot argue that while
these affections remain constant in character their causes may have been
different in other ages from what they are now. That is pure absurdity.
To claim that the religious mystic is in moments of exaltation brought
into contact with a "deeper reality" is to invite the retort that one
might make a similar claim on behalf of the inmates of a lunatic asylum.
We cannot, with any pretence to rationality, accept the verdicts of both
the neurologist and the exorcist. If we agree that certain states of
mind to-day have their origin in neural disorder, on what ground can we
believe that similar mental states occurring a thousand or two thousand
years ago were due to supernatural stimulation? We may be told that
there are more things in heaven and earth than are dreamed of in our
philosophy. This may be true, and while it is an observation that would
not occur to a fool, it needs no supreme wisdom for its excogitation,
and as generally used it is an excuse for idle speculation and grotesque
theory. Far more useful is the lesson, sadly needed, that there are few
things in heaven or earth that will not yield their secret to a method
of investigation that is sanely conceived and diligently employed.

The utter uselessness of accepting at its face value anyone's
explanation of the nature of his subjective experience, is well shown by
the once universal belief in witchcraft. If there is a single belief on
behalf of which a mass of apparently unimpeachable evidence could be
produced, it is this one. It