by their size,
complexion, limbs, and motions. And thirdly, because His operations are
regular and uniform. Whenever the course of nature is interrupted by a
miracle, men are ready to own the presence of a superior agent. But, when
we see things go on in the ordinary course they do not excite in us any
reflexion; their order and concatenation, though it be an argument of the
greatest wisdom, power, and goodness in their creator, is yet so constant
and familiar to us that we do not think them the immediate effects of a
Free Spirit; especially since inconsistency and mutability in acting,
though it be an imperfection, is looked on as a mark of freedom.

58. TENTH OBJECTION.--ANSWER.--Tenthly, it will be objected that
the notions we advance are inconsistent with several sound truths
in philosophy and mathematics. For example, the motion of the earth
is now universally admitted by astronomers as a truth grounded on
the clearest and most convincing reasons. But, on the foregoing
principles, there can be no such thing. For, motion being only an
idea, it follows that if it be not perceived it exists not; but the
motion of the earth is not perceived by sense. I answer, that tenet,
if rightly understood, will be found to agree with the principles
we have premised; for, the question whether the earth moves or no
amounts in reality to no more than this, to wit, whether we have
reason to conclude, from what has been observed by astronomers, that
if we were placed in such and such circumstances, and such or such a
position and distance both from the earth and sun, we should perceive the
former to move among the choir of the planets, and appearing in all
respects like one of them; and this, by the established rules of nature
which we have no reason to mistrust, is reasonably collected from the
phenomena.

59. We may, from the experience we have had of the train and succession
of ideas in our minds, often make, I will not say uncertain conjectures,
but sure and well--grounded predictions concerning the ideas we shall be
affected with pursuant to a great train of actions, and be enabled to
pass a right judgment of what would have appeared to us, in case we were
placed in circumstances very different from those we are in at present.
Herein consists the knowledge of nature, which may preserve its use and
certainty very consistently with what has been said. It will be easy to
apply this to whatever objections of the like sort may be dra