Mysticism in its larger sense is admittedly difficult to define. It
connotes a vast group of special experiences and speculations
which deal with material supposed to be beyond the reach of
sense and reason. It carries us back to the strangely illusive
"mysteries" of the Greeks, but is more definitely used in
connection with the most characteristic subtleties of the wizard
East, and with certain developments of the Platonic philosophy.
Extended exposition is not required. Suffice it to state what may
fairly be regarded as the three fundamental principles, or
doctrines, on which mystics of the orthodox schools generally
depend. These principles will be subjected to a free but friendly
criticism: considerable modifications will be suggested, and the
way thus prepared for the study of Nature Mysticism properly
so-called.

The three principles alluded to are the following. First, the true
mystic is one possessed by a desire to have communion with the
ultimately Real. Second, the ultimately Real is to be regarded as
a supersensuous, super-rational, and unconditional Absolute--
the mystic One. Third, the direct communion for which the
mystic yearns--the _unio mystica_--cannot be attained save by
passive contemplation, resulting in vision, insight, or ecstasy.

With a view to giving a definite and concrete turn to the critical
examination of these three fundamentals, let us take a passage
from a recently published booklet. The author tells how that on
a certain sunny afternoon he flung himself down on the bank of
a brimming mill-stream. The weir was smoothly flowing: the
mill-wheel still. He meditates on the scene and concludes thus:
"Perhaps we are never so receptive as when with folded hands