Chapter II: The Problem of Soul and Body

§ 1. The problem of psychophysical connection has to do with
the correlation of scientific abstractions, not of given
facts of experience. § 2. The “consciousness” of
Psychology is thus not the same thing as the finite
individual subject of experience, and Reality must not
be said to consist of “minds” in the psychologist’s
sense. Again, we must not assume _a priori_ that there
can be only _one_ working hypothesis of psychophysical
connection. § 3. The possible hypotheses may be reduced
to three, Epiphenomenalism, Parallelism, and
Interaction. § 4. _Epiphenomenalism_ is legitimate as a
methodological principle in Physiology; it is untenable
as a basis for Psychology because it implies the
reduction of psychical facts to mechanical law. § 5.
_Parallelism._ The arguments for Parallelism as
necessarily valid to Psychophysics because of its
congruity with the postulates of mechanical Physics, are
fallacious. We cannot assume that Psychology must
necessarily conform to these postulates. § 6. As a
working hypothesis Parallelism is available for many
purposes, but breaks down when we attempt to apply it to
the case of the initiation of fresh purposive reactions.
A teleological and a mechanical series cannot ultimately
be “parallel.” § 7. We are thus thrown back on the
hypothesis of _Interaction_ as the only one which
affords a consistent scheme for the correlation of
Physiology and Psychology. We have, however, to remember
that what the hypothesis correlates is scientific
symbols, not actual facts. The actuality represented by
both sets of symbols is the same thing, though the
psychological symbolism affords a wider and more
adequate representation of it than the physiological 313