BOOK I PART III
this kind, is composed of parts, which are of the
same nature both among themselves, and with
those, that compose the opposite probability.
Thirdly, We may establish it as a certain
maxim, that in all moral as well as natural
phaenomena, wherever any cause consists of
a number of parts, and the effect encreases
or diminishes, according to the variation of
that number, the effects properly speaking, is
a compounded one, and arises from the union
of the several effects, that proceed from each
part of the cause. Thus, because the gravity
of a body encreases or diminishes by the en-
crease or diminution of its parts, we conclude
that each part contains this quality and con-
tributes to the gravity of the whole. The ab-
sence or presence of a part of the cause is at-
tended with that of a proportionable part of the