No one can deny, that pain consists in the transition to a less perfection, and not in the less perfection itself: for a man cannot be pained, in so far as he partakes of perfection of any degree.

Neither can we say, that pain consists in the absence of a greater perfection.

For absence is nothing, whereas the emotion of pain is an activity; wherefore this activity can only be the activity of transition from a greater to a less perfection--in other words, it is an activity whereby a man's power of action is lessened or constrained (cf.III.xi.

note).

I pass over the definitions of merriment, stimulation, melancholy, and grief, because these terms are generally used in reference to the body, and are merely kinds of pleasure or pain.
IV.