Note.--Though this be so, no one will endeavour to hate anything, or to be affected with pain, for the sake of enjoying this greater pleasure; that is, no one will desire that he should be injured, in the hope of recovering from the injury, nor long to be ill for the sake of getting well. For everyone will always endeavour to persist in his being, and to ward off pain as far as he can. If the contrary is conceivable, namely, that a man should desire to hate someone, in order that he might love him the more thereafter, he will always desire to hate him. For the strength of love is in proportion to the strength of the hatred, wherefore the man would desire, that the hatred be continually increased more and more, and, for a similar reason, he would desire to become more and more ill, in order that he might take a greater pleasure in being restored to health: in such a case he would always endeavour to be ill, which (III. vi.) is absurd. PROP. XLV. If a man conceives, that anyone similar to himself hates anything also similar to himself, which he loves, he will hate that person. Proof.--The beloved object feels reciprocal hatred towards him who hates it (III. xl.); therefore the lover, in conceiving that anyone hates the beloved object, conceives the beloved thing as affected by hatred, in other words (III. xiii.), by pain; consequently he is himself affected by pain accompanied by the idea of the hater of the beloved thing as cause; that is, he will hate him who hates anything which he himself loves (III. xiii. note). Q.E.D. PROP. XLVI. If a man has been affected pleasurably or painfully by anyone, of a class or nation different from his own, and if the pleasure or pain has been accompanied by the idea of the said stranger as cause, under the general category of the class or nation: the man will feel love or hatred, not only to the individual stranger, but also to the whole class or nation whereto he belongs. Proof.--This is evident from III. xvi. PROP. XLVII. Joy arising from the fact, that anything we hate is destroyed, or suffers other injury, is never unaccompanied by a certain pain in us. Proof.--This is evident from III. xxvii. For in so far as we conceive a thing similar to ourselves to be affected with pain, we ourselves feel pain.