Theodor Haecker, Journal in the Night (Pantheon, 1950, tr. Dru), p. 29:
Many a man thinks to satisfy the great virtue of moderation by using all his shrewdness and bringing all his experience to bear upon limiting his pleasure to his capacity for pleasure. But simply by the fact of setting enjoyment as the end, he has radically violated the virtue.
A penetrating observation. What is the end or goal of moderation? Haecker is rejecting the notion that the purpose of moderation, conceived as a virtue, is to maximize the intensity and duration of pleasure. Of course, moderation can be used for that end -- but then it ceases to be a virtue.
For example, if I am immoderate in my use of alcohol and drugs, I will destroy my body, and with it my capacity for pleasure. So I must limit my pleasure to my capacity for pleasure. And the same holds for lack of moderation in eating and sexual indulgence. The sex monkey can kill you if you let him run loose. And even if one's lack of moderation does not lead to an early death, it can eventuate in a jadedness at odds with enjoyment.
So moderation can be recommended merely on hedonistic grounds. The true hedonist must of necessity be a man of moderation. If so, then the ill-starred John Belushi, who took the 'speedball' (heroin + cocaine) express to Kingdom Come, did not even succeed at being a very good hedonist.
But if enjoyment is the end of moderation, then moderation as a virtue is at an end. Haecker, however, does not tell us what the end of moderation as a virtue is. He would presumably not disagree with the claim that the goal of moderation as a virtue is a freedom from pleasure and pain that allows one to pursue higher goods. He who is enslaved to his lusts his simply not free to pursue a truer and higher life.