No pleasure is absolutely bad, although it is possible for it to be bad in relation to a given thing or circumstance. Most people identify bodily pleasure with pleasure as a whole. Bodily pleasures are good in a sense since they are the opposites of pains which are unquestionably bad, but things which satisfy a desire or ease an imperfection are pleasant only in an indirect sense. Real pleasure comes from the activity of what is healthy in us, and things that are naturally pleasant are those which stimulate positive activity. Anything in which we are capable of excess or deficiency cannot be a real pleasure, in the truest sense of the word.
Human nature is made up of two elements, one intellectual and the other material, and these two elements always act in opposition to each other. When these two elements are in a state of balance, the acts one performs seem neither pleasant nor painful. If human nature were simple and not subject to the pull of these opposites, it would be possible to find pleasure in a single unchanging activity while in a state of rest, what might be called an activity of immobility (i.e., an activity that attains its end at every moment of its existence), so that the truest pleasure would consist of rest rather than motion. To human beings, change always seems pleasant because of the material element within us, but the most perfect nature would be that which never needs to change.
The whole question of how it is possible for a man to have knowledge of right and wrong and to know what is good or best for himself and still to chronically act against this knowledge was a source of great concern for Greek thinkers. Aristotle's effort to explain this seeming paradox is original and interesting, but this element of human nature can only be understood adequately in terms of the findings of modern behavioral sciences.