Proof.--Envy is a species of hatred (III. xxiv. note) or (III. xiii. note) pain, that is (III. xi. note), a modification whereby a man's power of activity, or endeavour towards activity, is checked. But a man does not endeavour or desire to do anything, which cannot follow from his nature as it is given; therefore a man will not desire any power of activity or virtue (which is the same thing) to be attributed to him, that is appropriate to another's nature and foreign to his own; hence his desire cannot be checked, nor he himself pained by the contemplation of virtue in some one unlike himself, consequently he cannot envy such an one. But he can envy his equal, who is assumed to have the same nature as himself. Q.E.D. Note.--When, therefore, as we said in the note to III. lii., we venerate a man, through wonder at his prudence, fortitude, &c., we do so, because we conceive those qualities to be peculiar to him, and not as common to our nature; we, therefore, no more envy their possessor, than we envy trees for being tall, or lions for being courageous. PROP. LVI. There are as many kinds of pleasure, of pain, of desire, and of every emotion compounded of these, such as vacillations of spirit, or derived from these, such as love, hatred, hope, fear, &c., as there are kinds of objects whereby we are affected. Proof.--Pleasure and pain, and consequently the emotions compounded thereof, or derived therefrom, are passions, or passive states (III. xi. note); now we are necessarily passive (III. i.), in so far as we have inadequate ideas; and only in so far as we have such ideas are we passive (III. iii.); that is, we are only necessarily passive (II. xl. note), in so far as we conceive, or (II. xvii. and note) in so far as we are affected by an emotion, which involves the nature of our own body, and the nature of an external body. Wherefore the nature of every passive state must necessarily be so explained, that the nature of the object whereby we are affected be expressed. Namely, the pleasure, which arises from, say, the object A, involves the nature of that object A, and the pleasure, which arises from the object B, involves the nature of the object B; wherefore these two pleasurable emotions are by nature different, inasmuch as the causes whence they arise are by nature different. So again the emotion of pain, which arises from one object, is by nature different from the pain arising from another object, and, similarly, in the case of love, hatred, hope, fear, vacillation, &c.