or effect of matter," and that "body
and spirit together constitute matter." In our own country, Atkinson and
Martineau have not shrunk from the avowal of the same doctrine, or the
adoption of the most revolting consequences that can be deduced from it.
"Instinct, passion, thought, are effects of organized substances."--"Mind
is the consequence or product of the material man; it is not a thing
having a seat or home in the brain, but it is the manifestation or
expression of _the brain in action,_ as heat and light are of fire, and
fragrance of the flower."[148]

The doctrine of Materialism, as formerly taught by Dr. Priestley and
his followers, is in some respects similar to that which we have just
noticed, but in other respects differs from it, if not in its essential
nature, at least in its collateral adjuncts and its practical
applications. It resembles the theory of D'Holbach and Comte, in so far
as it affirms the doctrine of _unisubstancisme_, and rejects the idea of
a _dualism_ such as is implied in the common doctrine of Matter and
Spirit. But it differs from that theory, inasmuch as it is combined,
whether consistently or otherwise, with the recognition of a personal
God, a resurrection from the dead, and a future state of reward and
punishment. Dr. Priestley seems to have fluctuated for a time between
two opposite extremes,--that of _spiritualizing_ Matter, and that of
_materializing_ Mind; for, in a very remarkable passage, we find him
saying, "This scheme of _the immateriality of Matter_, as it may be
called, or rather, _the mutual penetration of Matter_, first occurred to
my friend Mr. Mitchell on reading 'Baxter on the Immateriality of the
Soul.'"[149] But at length he settled down in the fixed belief of
Materialism, as he had always held the principle of _unisubstancisme_.
He held throughout that "Man does not consist of two principles so
essentially different from each other as Matter and Spirit, but the
whole man is of _one uniform composition_; and that either the material
or the immaterial part of the universal system is superfluous."[150] He
attempts, therefore, to show, that sensation, perception, and
thought,--the common properties of _mind_,--are not incompatible with
extension, attraction, and repulsion, which he conceives to be the only
essential properties of _matter;_ that both classes of properties may
possibly belong to the same subject; and that hence no second substance
is necessary to acco