for practical purposes to have merely a general
knowledge of them. However, it is established from the
definitions of the emotions, which we have set forth, that they
all spring from desire, pleasure, or pain, or, rather, that there
is nothing besides these three; wherefore each is wont to be
called by a variety of names in accordance with its various
relations and extrinsic tokens. If we now direct our attention
to these primitive emotions, and to what has been said concerning
the nature of the mind, we shall be able thus to define the
emotions, in so far as they are referred to the mind only.

GENERAL DEFINITION OF THE EMOTIONS

Emotion, which is called a passivity of the soul, is a
confused idea, whereby the mind affirms concerning its body, or
any part thereof, a force for existence (existendi vis) greater
or less than before, and by the presence of which the mind is
determined to think of one thing rather than another.

Explanation--I say, first, that emotion or passion of the soul
is a confused idea. For we have shown that the mind is only
passive, in so far as it has inadequate or confused ideas. (III.
iii.) I say, further, whereby the mind affirms concerning its
body or any part thereof a force for existence greater than
before. For all the ideas of bodies, which we possess, denote
rather the actual disposition of our own body (II. xvi. Coroll.
ii.) than the nature of an external body. But the idea which
constitutes the reality of an emotion must denote or express the
disposition of the body, or of some part thereof, because its
power of action or force for existence is increased or
diminished, helped or hindered. But it must be noted that, when
I say a greater or less force for existence than before, I do not
mean that the mind compares the present with the past disposition
of the body, but that the idea which constitutes the reality of
an emotion affirms something of the body, which, in fact,
involves more or less of reality than before.

And inasmuch as the essence of mind consists in the fact (II.
xi., xiii.), that it affirms the actual existence of its own
body, and inasmuch as we understand by perfection the very
essence of a thing, it follows that the mind passes to greater or
less perfection, when it happens to affirm concerning its own
body, or any part thereof, something involving more or less
reality than before.

When, therefore, I said above that the power of the mind is
increa