f;
further, that appetite is the essence of man, in so far as it is
determined to act in a way tending to promote its own
persistence. But, in the same note, I also remarked that,
strictly speaking, I recognize no distinction between appetite
and desire. For whether a man be conscious of his appetite or
not, it remains one and the same appetite. Thus, in order to
avoid the appearance of tautology, I have refrained from
explaining desire by appetite; but I have take care to define it
in such a manner, as to comprehend, under one head, all those
endeavours of human nature, which we distinguish by the terms
appetite, will, desire, or impulse. I might, indeed, have said,
that desire is the essence of man, in so far as it is conceived
as determined to a particular activity; but from such a
definition (cf. II. xxiii.) it would not follow that the mind can
be conscious of its desire or appetite. Therefore, in order to
imply the cause of such consciousness, it was necessary to add,
in so far as it is determined by some given modification, &c.
For, by a modification of man's essence, we understand every
disposition of the said essence, whether such disposition be
innate, or whether it be conceived solely under the attribute of
thought, or solely under the attribute of extension, or whether,
lastly, it be referred simultaneously to both these attributes.
By the term desire, then, I here mean all man's endeavours,
impulses, appetites, and volitions, which vary according to each
man's disposition, and are, therefore, not seldom opposed one to
another, according as a man is drawn in different directions, and
knows not where to turn.

II. Pleasure is the transition of a man from a less to a greater
perfection.

III. Pain is the transition of a man from a greater to a less
perfection.

Explanation--I say transition: for pleasure is not perfection
itself. For, if man were born with the perfection to which he
passes, he would possess the same, without the emotion of
pleasure. This appears more clearly from the consideration of
the contrary emotion, pain. No one can deny, that pain consists
in the transition to a less perfection, and not in the less
perfection itself: for a man cannot be pained, in so far as he
partakes of perfection of any degree. Neither can we say, that
pain consists in the absence of a greater perfection. For
absence is nothing, whereas the emotion of pain is an activity;
wherefore this activity c