conceiving force to be anything like volition,
drives another school of thinkers into the denial of any connection,
save that of succession, between cause and effect.

* * * * *

To sum up. If the materialist affirms that the universe and all its
phenomena are resolvable into matter and motion, Berkeley replies,
True; but what you call matter and motion are known to us only as
forms of consciousness; their being is to be conceived or known; and
the existence of a state of consciousness, apart from a thinking mind,
is a contradiction in terms.

I conceive that this reasoning is irrefragable. And therefore, if
I were obliged to choose between absolute materialism and absolute
idealism, I should feel compelled to accept the latter alternative.
Indeed, upon this point Locke does, practically, go as far in the
direction of idealism, as Berkeley, when he admits that "the simple
ideas we receive from sensation and reflection are the boundaries of
our thoughts, beyond which the mind, whatever efforts it would make,
is not able to advance one jot."--Book II. chap, xxiii. Sec. 29.

But Locke adds, "Nor can it make any discoveries when it would pry
into the nature and hidden causes of these ideas."

Now, from this proposition, the thorough materialists dissent as much,
on the one hand, as Berkeley does, upon the other hand.

The thorough materialist asserts that there is a something which he
calls the "substance" of matter; that this something is the cause of
all phenomena, whether material or mental; that it is self-existent
and eternal, and so forth.

Berkeley, on the contrary, asserts with equal confidence that there is
no substance of matter, but only a substance of mind, which he terms
spirit; that there are two kinds of spiritual substance, the one
eternal and uncreated, the substance of the Deity, the other created,
and, once created, naturally eternal; that the universe, as known
to created spirits, has no being in itself, but is the result of
the action of the substance of the Deity on the substance of those
spirits.

In contradiction to which bold assertion, Locke affirms that we simply
know nothing about substance of any kind.[1]

[Footnote 1: Berkeley virtually makes the same confession of
ignorance, when he admits that we can have no idea or notion of a
spirit ("Principles of Human Knowledge," Sec. 138); and the way in which
he tries to escape the consequences of this admissio