ying the beloved
object. Q.E.D.

Note.--This hatred towards an object of love joined with envy
is called Jealousy, which accordingly is nothing else but a
wavering of the disposition arising from combined love and
hatred, accompanied by the idea of some rival who is envied.
Further, this hatred towards the object of love will be greater,
in proportion to the pleasure which the jealous man had been wont
to derive from the reciprocated love of the said object; and
also in proportion to the feelings he had previously entertained
towards his rival. If he had hated him, he will forthwith hate
the object of his love, because he conceives it is pleasurably
affected by one whom he himself hates: and also because he is
compelled to associate the image of his loved one with the image
of him whom he hates. This condition generally comes into play
in the case of love for a woman: for he who thinks, that a woman
whom he loves prostitutes herself to another, will feel pain, not
only because his own desire is restrained, but also because,
being compelled to associate the image of her he loves with the
parts of shame and the excreta of another, he therefore shrinks
from her.

We must add, that a jealous man is not greeted by his beloved
with the same joyful countenance as before, and this also gives
him pain as a lover, as I will now show.

PROP. XXXVI. He who remembers a thing, in which he has once
taken delight, desires to possess it under the same circumstances
as when he first took delight therein.

Proof.--Everything, which a man has seen in conjunction with
the object of his love, will be to him accidentally a cause of
pleasure (III. xv.); he will, therefore, desire to possess it,
in conjunction with that wherein he has taken delight; in other
words, he will desire to possess the object of his love under the
same circumstances as when he first took delight therein. Q.E.D.

Corollary.--A lover will, therefore, feel pain if one of the
aforesaid attendant circumstances be missing.

Proof.--For, in so far as he finds some circumstance to be
missing, he conceives something which excludes its existence. As
he is assumed to be desirous for love's sake of that thing or
circumstance (by the last Prop.), he will, in so far as he
conceives it to be missing, feel pain (III. xix.). Q.E.D.

Note.--This pain, in so far as it has reference to the absence
of the object of love, is called Regret.

PROP. XXXVII. Desire arising