he action and reaction proper to life itself, whereby
it forever springs freshly from its source. The latter form of
expression is mystical, in the true meaning of that term. We close our
eyes to the outward appearance, in order that we may directly confront a
mystery which is already past before there is any visible indication
thereof. Though the imagination engaged in this mystical apprehension
borrows its symbols or analogues from observation and experience, yet
these symbols are spiritually regarded by looking at life on its living
side, and abstracted as far as possible from outward embodiment. We
especially affect physiological analogues because, being derived from
our experience, we may the more readily have the inward regard of them;
and by passing from one physiological analogue to another, and from all
these to those furnished by the processes of nature outside of our
bodies, we come to an apprehension of the action and reaction proper to
life itself as an idea independent of all its physical representations.

Thus we trace the rhythmic beating of the pulse to the systole and
diastole of the heart, and we note a similar alternation in the
contraction and relaxation of all our muscles. Breathing is alternately
inspiration and expiration. Sensation itself is by beats, and falls into
rhythm. There is no uninterrupted strain of either action or
sensibility; a current or a contact is renewed, having been broken. In
psychical operation there is the same alternate lapse and resurgence.
Memory rises from the grave of oblivion. No holding can be maintained
save through alternate release. Pulsation establishes circulation, and
vital motions proceed through cycles, each one of which, however minute,
has its tropic of Cancer and of Capricorn. Then there are the larger
physiological cycles, like that wherein sleep is the alternation of
waking. Passing from the field of our direct experience to that of
observation, we note similar alternations, as of day and night, summer
and winter, flood and ebb tide; and science discloses them at every
turn, especially in its recent consideration of the subtle forces of
Nature, leading us back of all visible motions to the pulsations of
the ether....

In considering the action and reaction proper to life itself, we here
dismiss from view all measured cycles, whose beginning and end are
appreciably separate; our regard is confined to living moments, so fleet
that their beginning and endi