back a thousand years from his time, through the philosophy of Proclus,
Zeno, Aristotle,[40] Plato, Socrates, Parmenides, and Pythagoras. It is
absurd to suppose any production or effect to be more excellent than its
cause. That which really produces motion, cannot itself be inert; and that
which actually causes the human mind to think and reason, cannot itself be
devoid of intelligence. "For knowledge can alone produce knowledge." [41] A
doctrine apparently at variance with this, has recently been taught, with
great confidence, among the professed discoveries of _Phrenology_. How much
truth there may be in this new "_science_," as it is called, I am not
prepared to say; but, as sometimes held forth, it seems to me not only to
clash with some of the most important principles of mental philosophy, but
to make the power of thought the result of that which is in itself inert
and unthinking. Assuming that the primitive faculties of the human
understanding have not been known in earlier times, it professes to have
discovered, in the physical organization of the brain, their proper source,
or essential condition, and the true index to their measure, number, and
distribution. In short, the leading phrenologists, by acknowledging no
spiritual substance, virtually deny that ancient doctrine, "It is not in
flesh to think, or bones to reason," [42] and make the mind either a
material substance, or a mere mode without substantial being.

14. "The
doctrine of _immaterial substances_," says Dr. Spurzheim, "is not
sufficiently amenable to the test of observation; it is founded on belief,
and only supported by hypothesis."--_Phrenology_, Vol. i, p. 20. But it
should be remembered, that our notion of material substance, is just as
much a matter of hypothesis. All accidents, whether they be qualities or
actions, we necessarily suppose to have some support; and this we call
_substance_, deriving the term from the Latin, or _hypostasis_, if we
choose to borrow from the Greek. But what this substance, or hypostasis,
is, independently of its qualities or actions, we know not. This is clearly
proved by Locke. What do we mean by _matter_? and what by _mind_? _Matter_
is that which is solid, extended, divisible, movable, and occupies space.
_Mind_ is that which thinks, and wills, and reasons, and remembers, and
worships. Here are qualities in the one case; operations in the other. Here
are two definitions as totally distinct as any two can be; a