e know not to
exist in the present, and which we conceive as contingent, is far
fainter, than if we conceive the thing to be present with us.

Proof.--Emotion towards a thing, which we conceive to exist,
is more intense than it would be, if we conceived the thing as
future (IV. ix. Coroll.), and is much more vehement, than if the
future time be conceived as far distant from the present (IV.
x.). Therefore an emotion towards a thing, whose period of
existence we conceive to be far distant from the present, is far
fainter, than if we conceive the thing as present; it is,
nevertheless, more intense, than if we conceived the thing as
contingent, wherefore an emotion towards a thing, which we regard
as contingent, will be far fainter, than if we conceived the
thing to be present with us. Q.E.D.

PROP. XIII. Emotion towards a thing contingent, which we know
not to exist in the present, is, other conditions being equal,
fainter than an emotion towards a thing past.

Proof.--In so far as we conceive a thing as contingent, we are
not affected by the image of any other thing, which asserts the
existence of the said thing (IV. Def. iii.), but, on the other
hand (by hypothesis), we conceive certain things excluding its
present existence. But, in so far as we conceive it in relation
to time past, we are assumed to conceive something, which recalls
the thing to memory, or excites the image thereof (II. xviii. and
note), which is so far the same as regarding it as present (II.
xvii. Coroll.). Therefore (IV. ix.) an emotion towards a thing
contingent, which we know does not exist in the present, is
fainter, other conditions being equal, than an emotion towards a
thing past. Q.E.D.

PROP. XIV. A true knowledge of good and evil cannot check any
emotion by virtue of being true, but only in so far as it is
considered as an emotion.

Proof.--An emotion is an idea, whereby the mind affirms of its
body a greater or less force of existing than before (by the
general Definition of the Emotions); therefore it has no
positive quality, which can be destroyed by the presence of what
is true; consequently the knowledge of good and evil cannot, by
virtue of being true, restrain any emotion. But, in so far as
such knowledge is an emotion (IV. viii.) if it have more strength
for restraining emotion, it will to that extent be able to
restrain the given emotion. Q.E.D.

PROP. XV. Desire arising from the knowledge of good and bad can