Proof.—That, which we conceive to affect an object of our love pleasurably or painfully, affects us also pleasurably or painfully (III. xxi.). But the mind (III. xii.) endeavours, as far as possible, to conceive those things which affect us pleasurably; in other words (II. xvii. and Coroll.), it endeavours to regard them as present. And, contrariwise (III. xiii.), it endeavours to exclude the existence of such things as affect us painfully; therefore, we endeavour to affirm concerning ourselves, and concerning the loved object, whatever we conceive to affect ourselves, or the love object pleasurably. Q.E.D.
PROP. XXVI. We endeavour to affirm, concerning that which we hate, everything which we conceive to affect it painfully; and, contrariwise, we endeavour to deny, concerning it, everything which we conceive to affect it pleasurably.
Proof.—This proposition follows from III. xxiii., as the foregoing proposition followed from III. xxi.
Note.—Thus we see that it may readily happen, that a man may easily think too highly of himself, or a loved object, and, contrariwise, too meanly of a hated object. This feeling is called pride, in reference to the man who thinks too highly of himself, and is a species of madness, wherein a man dreams with his eyes open, thinking that he can accomplish all things that fall within the scope of his conception, and thereupon accounting them real, and exulting in them, so long as he is unable to conceive anything which excludes their existence, and determines his own power of action. Pride, therefore, is pleasure springing from a man thinking too highly of himself. Again, the pleasure which arises from a man thinking too highly of another is called over—esteem. Whereas the pleasure which arises from thinking too little of a man is called disdain.
PROP. XXVII. By the very fact that we conceive a thing, which is like ourselves, and which we have not regarded with any emotion, to be affected with any emotion, we are ourselves affected with a like emotion (affectus).
Proof.—The images of things are modifications of the human body, whereof the ideas represent external bodies as present to us (II. xvii.); in other words (II. x.), whereof the ideas involve the nature of our body, and, at the same time, the nature of the external bodies as present. If, therefore, the nature of the external body be similar to the nature of our body, then the idea which we form of the external body will involve a modification of our own body similar to the modification of the external body. Consequently, if we conceive anyone similar to ourselves as affected by any emotion, this conception will express a modification of our body similar to that emotion. Thus, from the fact of conceiving a thing like ourselves to be affected with any emotion, we are ourselves affected with a like emotion. If, however, we hate the said thing like ourselves, we shall, to that extent, be affected by a contrary, and not similar, emotion. Q.E.D.
Note I.—This imitation of emotions, when it is referred to pain, is called compassion (cf. III. xxii. note); when it is referred to desire, it is called emulation, which is nothing else but the desire of anything, engendered in us by the fact that we conceive that others have the like desire.
Corollary I.—If we conceive that anyone, whom we have hitherto regarded with no emotion, pleasurably affects something similar to ourselves, we shall be affected with love towards him. If, on the other hand, we conceive that he painfully affects the same, we shall be affected with hatred towards him.
Proof.—This is proved from the last proposition in the same manner as III. xxii. is proved from III. xxi.
Corollary II.—We cannot hate a thing which we pity, because its misery affects us painfully.