As the nature of the body is composite, reason convinces us that it
cannot last perpetually, and our senses show it to us dissolved,
destroyed, and decayed, because the elements that compose it return
to join the elements of the same nature, altering, destroying them
and each other, especially when this chaos is abandoned to the soul,
which alone keeps her parts combined. Even if a body were taken alone,
it would not be a unity; it may be analyzed into form and matter,
principles that are necessary to the constitution of all bodies, even
of those that are simple.[32] Besides, as they contain extension,
the bodies can be cut, divided into infinitely small parts, and thus
perish.[33] Therefore if our body is a part of ourselves,[34] not all
of us is immortal; if the body is only the instrument of the soul, as
the body is given to the soul only for a definite period, it still is
by nature perishable.