hinking with Mr. Whiston, and fancied that
comets were always the forerunners of some great calamity which was to
befall mankind. Sir Isaac Newton, on the contrary, suspected that they
are very beneficent, and that vapours exhale from them merely to nourish
and vivify the planets, which imbibe in their course the several
particles the sun has detached from the comets, an opinion which, at
least, is more probable than the former. But this is not all. If this
power of gravitation or attraction acts on all the celestial globes, it
acts undoubtedly on the several parts of these globes. For in case
bodies attract one another in proportion to the quantity of matter
contained in them, it can only be in proportion to the quantity of their
parts; and if this power is found in the whole, it is undoubtedly in the
half; in the quarters in the eighth part, and so on in _infinitum_.

This is attraction, the great spring by which all Nature is moved. Sir
Isaac Newton, after having demonstrated the existence of this principle,
plainly foresaw that its very name would offend; and, therefore, this
philosopher, in more places than one of his books, gives the reader some
caution about it. He bids him beware of confounding this name with what
the ancients called occult qualities, but to be satisfied with knowing
that there is in all bodies a central force, which acts to the utmost
limits of the universe, according to the invariable laws of mechanics.

It is surprising, after the solemn protestations Sir Isaac made, that
such eminent men as Mr. Sorin and Mr. de Fontenelle should have imputed
to this great philosopher the verbal and chimerical way of reasoning of
the Aristotelians; Mr. Sorin in the Memoirs of the Academy of 1709, and
Mr. de Fontenelle in the very eulogium of Sir Isaac Newton.

Most of the French (the learned and others) have repeated this reproach.
These are for ever crying out, "Why did he not employ the word
_impulsion_, which is so well understood, rather than that of
_attraction_, which is unintelligible?"

Sir Isaac might have answered these critics thus:--"First, you have as
imperfect an idea of the word impulsion as of that of attraction; and in
case you cannot conceive how one body tends towards the centre of another
body, neither can you conceive by what power one body can impel another.

"Secondly, I could not admit of impulsion; for to do this I must have
known that a celestial matter was the agent. But s