erable body
subsists only so long as the individual life lasts. At the instant of
the first beginning of the individual organism, at the moment of
generation, this imponderable "soul" passes into the body, and at the
instant of death, at the annihilation of the living individual, it
again quits the body. This mystical or dualistic soul-hypothesis,
which, as is well known, is to this day universally accepted, is
fundamentally vitalistic, inasmuch as it regards the force which is
bound up with the soul-substance, like the "vital force" of a past
time, as a peculiar force quite independent of mechanical forces. This
force does not depend on the material phenomena of motion, and is
quite independent of the mechanics of atoms. The highest law of modern
natural science, the law of the conservation of force, has,
therefore, no application in the region of soul-life, and that
mechanical causality which prevails throughout all the processes of
nature does not exist for the soul. The Psyche, in a word, is a
supernatural phenomenon, and the supernatural department of the
spiritual world stands free and independent of the natural department
of the material world.

If we now compare the psychological views of the youthful and
unprejudiced Virchow of Wuerzburg with those of the older and mystical
Virchow of Berlin, there can be no doubt in the minds of the impartial
that the former, a quarter of a century ago, was as decided and
logical a monist as the latter is at present a confessed and convicted
dualist. The distinguished position which Virchow, twenty-five years
since, won by his natural conception of the nature of man, and the
great fame which he then earned in the fight for the truth, rest
precisely on this, that on every occasion he maintained with his
utmost vigour the unity of all vital phenomena, and asserted their
mechanical character. All organic life, even the soul-life, rests on
mechanical principles, on that causal mechanism of which Kant said
that "it alone contained a practical interpretation of nature," and
that "without it no natural science can exist." On this point Virchow
says well in his discourse on "Efforts at Unity in Scientific
Medicine," 1849:--"Life is only a peculiar sort of mechanics, though
it is indeed the most complex form of mechanics; that in which the
usual mechanical laws fall under the most unusual and manifold
conditions. Thus life, compared with the universal processes of motion
in nature, i