On the other hand, the pleasures attached to one exercise impede the mind in regard to other exercises; thus men fond of the flute cannot listen to a speaker with attention, if any one is playing the flute near them.

What we delight in doing, we are more likely to do well; what we feel pain in doing, we are not likely to do well.

And thus each variety of exercise is alike impeded by the pains attached to itself, and by the pleasures attached to other varieties.
Among these exercises or acts, some are morally good, others morally bad; the desires of the good are also praise-worthy, the desires of the bad are blameable; but if so, much more are the pleasures attached to the good exercises, good pleasures--and the pleasures attached to the bad exercises, bad pleasures.

For the pleasures attached to an exercise are more intimately identified with that exercise than the desire of it can be.

The pleasure of the exercise, and the exercise itself, are indeed so closely identified one with the other, that to many they appear the same.