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.
Thus, there are necessarily as many kinds of pleasure, pain, love, hatred, &c., as there are kinds of objects whereby we are affected.