The Subconscious is:

_1 Vast yet Explorable_

The fraction that could accurately show the relation of the conscious
to the unconscious part of ourselves would have such a small numerator
and such a huge denominator that we might well wonder where
consciousness came in at all.[26] Some one has likened the
subconscious to the great far-reaching depths of the Mammoth Cave, and
consciousness to the tiny, flickering lamp which we carry to light our
way in the darkness. However, ever the subconscious mind is becoming
explorable, and it may be that science is giving the tiny lamp the
revealing power of a great searchlight.

[Footnote 26: "The entire active life of the individual may be
represented by a fraction, the numerator of which is any particular
moment, the denominator is the rich inheritance of the
past."--Jelliffe: "The Technique of Psychoanalysis," _Psychoanalytic
Review,_ Vol. III, No. 2, p. 164.]

_2 Ancient yet Modern_

The lowest layers of the subconscious, represented by the instincts,
are as old as life itself, with their lineage reaching back in direct
and unbroken line to the first living things on the ooze of the ocean
floor. The higher strata are more modern, full, and accurate records
of our own lifetime, beginning with our first cry and ending with
to-day's thoughts.