nature do all proceed on the supposition
that corporeal substance or Matter doth really exist. To this I ANSWER
that there is not any one PHENOMENON explained on that supposition which
may not as well be explained without it, as might easily be made appear
by an INDUCTION OF PARTICULARS. To explain the PHENOMENA, is all one as
to show why, upon such and such occasions, we are affected with such and
such ideas. But (1) how Matter should operate on a Spirit, or produce any
idea in it, is what no philosopher will pretend to explain; it is
therefore evident there can be no use of Matter in natural philosophy.
Besides, (2) they who attempt to account for things do it not by CORPOREAL
SUBSTANCE, but by figure, motion, and other qualities, which are in truth
no more than mere ideas, and, therefore, cannot be the cause of anything,
as has been already shown. See sect. 25.

51. SEVENTH OBJECTION.--ANSWER.--Seventhly, it will upon this be
demanded whether it does not seem ABSURD TO TAKE AWAY NATURAL CAUSES,
AND ASCRIBE EVERYTHING TO THE IMMEDIATE OPERATION OF SPIRITS? We
must no longer say upon these principles that fire heats, or water
cools, but that a Spirit heats, and so forth. Would not a man be
deservedly laughed at, who should talk after this manner? I ANSWER,
he would so; in such things we ought to THINK WITH THE LEARNED,
AND SPEAK WITH THE VULGAR. They who to demonstration are convinced
of the truth of the Copernican system do nevertheless say "the sun
rises," "the sun sets," or "comes to the meridian"; and if they
affected a contrary style in common talk it would without doubt appear
very ridiculous. A little reflexion on what is here said will make it
manifest that the common use of language would receive no manner of
alteration or disturbance from the admission of our tenets.

52. IN THE ORDINARY AFFAIRS OF LIFE, ANY PHRASES MAY BE RETAINED, so long
as they excite in us proper sentiments, or dispositions to act in such a
manner as is necessary for our WELL-BEING, how false soever they may be
if taken in a strict and SPECULATIVE SENSE. Nay, this is unavoidable,
since, propriety being regulated by CUSTOM, language is suited to the
RECEIVED opinions, which are not always the truest. Hence it is
impossible, even in the most rigid, philosophic reasonings, so far to
alter the bent and genius of the tongue we speak, as never to give a
handle for cavillers to pretend difficulties and inconsistencies. But, a
fair and ingenuou