LXIV. From all that has been said, it may be evidently concluded, that
we know nothing of the nature of that principal object of physics, _an
ens mobile_, either taken as confined to individuals, or considered
with respect to the species, or contemplated in an abstracted sense,
as relating to the gradations, of lowest, inferior, or supreme. What
one sect affirms, another denies, and the worst is, that, attend to the
reasoning of which of them you will, you will find the arguments against
the system of each, stronger than the proofs in favour of it. On this
account, Lactantius said wisely, that philosophers have swords, but no
shields: _Gladium habent, scutum non habent._ They produce penetrating
arguments wherewith to assail the opinions of their opponents, but not
solid solutions, wherewith to defend their own. What can we do then in
such a case? Why nothing but suspend our judgment, till some angel shall
decide the contest.
LXV. Perhaps some one will remark to me, that the substantial nature
of things is at a great distance from our view, and that therefore
it is not wonderful, that we have not yet penetrated into the inmost
recesses of philosophy; for that without advancing so far, we may find
sufficient matter whereon to exercise our speculations, in contemplating
the ordinary phenomena of nature, and by endeavouring to discover their
proximate causes; which attempt, may possibly be crowned with success, by
observing and reasoning upon every species of movement which is performed
by an entity, that has motion or circulation, according to the nature of
such an entity.
LXVI. I will acknowledge, that philosophy helps us to reason upon natural
phenomena, and to enquire into their more immediate causes; but in doing
this, we frequently wander in the dark, and are much exposed to be
interrupted by impediments, produced by ignorance and doubts; except it
is in the case of a few truths, the discovery of which, we owe to the
light of experience; and this fact is evinced, with respect to the very
instance of motion which has been just alledged.
LXVII. With regard to the movements of generation, corruption,
alteration, augmentation, and the rest, which are considered as distinct
from local motion, you can find nothing that is not questionable,
both in the schools of the Aristotelites, and in those of the modern
philosophers. The very definition of motion in general, which was given
by Aristotle, some reject as obscure, others as perplexed, and others
as nugatory. The movements we are now treating of, in the opinion
of Aristotle, are acquisitions of new forms, either substantial, or
accidental; but the Moderns, who deny the existence of all material
forms, object to this definition of those movements. Even among the
Aristotelites themselves, it is not agreed, whether motion is not
influenced by passion; nor whether the first, is not obedient as a
passive agent to the last. And thus in every thing else, it is all
question, and all dispute.