ne whose
idea cannot exist in the mind; but a very little reflection will show
that it is as impossible that a man, from the necessity of his nature,
should endeavor not to exist, or to be changed into some other form, as
it is that something should be begotten from nothing.

The endeavor after self-preservation is the essence itself of a thing.
If, therefore, any virtue could be conceived prior to this of
self-preservation, the essence itself of the thing would be conceived as
prior to itself, which (as is self-evident) is absurd.

The endeavor after self-preservation is the primary and only foundation
of virtue. For prior to this principle no other can be conceived, and
without it no virtue can be conceived.

No one endeavors to preserve his own being for the sake of another
object. For if a man endeavored to preserve his being for the sake of
any other object, this object would then become the primary foundation
of virtue (as is self-evident), which is an absurdity.

No one can desire to be happy, to act well and live well, who does not
at the same time desire to be, to act, and to live, that is to say,
actually to exist.

II

To act absolutely in conformity with virtue is nothing but acting
according to the laws of our own proper nature. But only in so far as
we understand do we act. Therefore, to act in conformity with virtue is
nothing but acting, living, and preserving our being as reason directs,
and doing so from the ground of seeking our own profit.[30]

In so far as a man is determined to action because he has inadequate
ideas he suffers, that is to say, he does something which through his
essence alone cannot be perceived, that is to say, which does not follow
from his virtue. But in so far as he is determined to any action because
he understands, he acts, that is to say he does something which is
perceived through his essence alone, or which adequately follows from
his virtue.

_The Highest Virtue of Reason_

All efforts which we make through reason are nothing but efforts to
understand, and the mind, in so far as it uses reason, adjudges nothing
as profitable to itself excepting that which conduces to understanding.

The mind, in so far as it reasons, desires nothing but to understand,
nor does it adjudge anything to be profitable to itself excepting what
conduces to understanding. But the mind possesses no certitude, unless
in so far as it possesses adequate ideas, or in so far as it reaso