It need only be remembered that all pleasure is negative, and that pain is positive in its nature, in order to see that the passions can never be a source of happiness, and that age is not the less to be envied on the ground that many pleasures are denied it. For every sort of pleasure is never anything more than the quietive of some need or longing; and that pleasure should come to an end as soon as the need ceases, is no more a subject of complaint than that a man cannot go on eating after he has had his dinner, or fall asleep again after a good night's rest.
