s of science in the nineteenth century was one long conquest of
territory in the land of the impossible. Inventors and inventions have
met with incredulity and mockery. Railways, steamships, aeroplanes,
telegraphy, telephony and cinematographs have all emerged from the
region of "impossibilities." Roentgen-rays and radium have descended from
the sphere of miracles.

Experience should endow us with cautiousness in proclaiming
impossibilities of the future. The study of psychic science has imposed
no greater strain on my reason than the attempt to explain the mysteries
of biology and astronomy. Observation and classification do not
necessarily imply elucidation. The miracle of the foetus taking human
shape and soul, or of the oak rising out of the acorn and the brown
earth is to me as baffling as the materialization of a spirit. The
marvels of the cell-life and the daily chemistry which maintain the body
charm my attention as much as the mysterious clouds of light with which
spirits are wont to signalize their presence in the seance-room. I have
sat for hours on a summer night by the Mediterranean watching the
phosphorescent waves throw a luminous spray over the shore, and
meditating on the inexhaustible fertility of the sea. And I have watched
with the same intense wonder the phenomena of the soul illuminated by
the _daimon_ of inner vision and the infinite manifestations of the
power of spirit over matter. From the point of view of science there is
no clearly defined frontier between the natural and the supernatural,
the commonplace and the miraculous. All is soil for the plough, all
defies our designs for complete explanation. From the point of view of
religious emotion, there is the greatest possible difference between the
sciences of psychic force and those that seek to probe the mysteries of
the physical world. The question of the immortality of the human soul is
infinitely more engrossing than that of the formation of the skull of
neolithic man. The strictly evidential demonstration of communion
between the living and the dead might be almost negligible in quantity,
and yet the importance of one rap from the world of discarnate spirits,
scientifically demonstrated, would outweigh tomes of theories in
physics.

True, those who live in the spirit need no demonstrations provided by
scientific investigators of psychic problems. The mystic consciousness
with its intuition of immortality, its sensitiveness to the vibrat