uently the one hypothesis labours under the same difficulties in
this respect with the other.

Thirdly, It has been objected to the system of one simple substance in
the universe, that this substance being the support or substratum of
every thing, must at the very same instant be modifyed into forms,
which are contrary and incompatible. The round and square figures are
incompatible in the same substance at the same time. How then is it
possible, that the same substance can at once be modifyed into
that square table, and into this round one? I ask the same question
concerning the impressions of these tables; and find that the answer is
no more satisfactory in one case than in the other.

It appears, then, that to whatever side we turn, the same difficulties
follow us, and that we cannot advance one step towards the establishing
the simplicity and immateriality o the soul, without preparing the
way for a dangerous and irrecoverable atheism. It is the same case, if
instead o calling thought a modification of the soul, we should give it
the more antient, and yet more modish name of an action. By an action we
mean much the same thing, as what is commonly called an abstract
mode; that is, something, which, properly speaking, is neither
distinguishable, nor separable from its substance, and is only conceived
by a distinction of reason, or an abstraction. But nothing is gained by
this change of the term of modification, for that of action; nor do we
free ourselves from one single difficulty by its means; as will appear
from the two following reflexions.

First, I observe, that the word, action, according to this explication
of it, can never justly be applied to any perception, as derived from
a mind or thinking substance. Our perceptions are all really different,
and separable, and distinguishable from each other, and from everything
else, which we can imagine: and therefore it is impossible to conceive,
how they can be the action or abstract mode of any substance. The
instance of motion, which is commonly made use of to shew after what
manner perception depends, as an action, upon its substance, rather
confounds than instructs us. Motion to all appearance induces no real
nor essential change on the body, but only varies its relation to other
objects. But betwixt a person in the morning walking a garden with
company, agreeable to him; and a person in the afternoon inclosed in a
dungeon, and full of terror, despair, and resent