The reason we should do nothing for the sake of pleasure is that it is precisely this that enslaves us. Who is oriented toward pleasure in his life will not be able to stand the difficulties, challenges, and misfortunes of life, much less danger and death. To be sure, one could claim that virtuous pursuit of pleasure will be good, but this is just to say that pleasure is not the highest good, not a primary good, but at best a supplementary one. And it is easy enough to find examples of people corrupted by the pursuit of pleasure.
Book XII
It is true that bad men pursuing pleasure are likely not to be entirely tranquil in mind, but this does not imply that they do not achieve their goal of pleasure. The wise, on the contrary, are restrained in their pleasures. Epicurus himself held that restraint was important for pleasure; but the masses try to cover their dissoluteness with his philosophy, seizing on any excuse he might provide for thinking that pleasure is a fundamental good, despite the Epicurean emphasis on temperance. Thus, he admonishes his Epicurean interlocutor, the insistence of the Epicureans on pleasure tends to obscure their better part; it is in this sense that it is harmful.
Book XIII
Seneca himself regards Epicurean ideas as entirely good and appropriate, although it is odd for a Stoic to say so. Epicurus, despite all the talk of pleasure, only allows it a very narrow scope, and governs pleasure by much the same rule that the Stoics govern habits: submission to nature. Both the Stoic and the Epicurean have a problem with luxury and craving because they do not rest satisfied with what is appropriate to nature. Unlike most Stoics, then, Seneca refuses to treat the Epicurean school as "the teacher of crime", but he does think it unsurprising that it has the bad reputation it does. It is like a brave man wearing a prissy dress; it doesn't eliminate the bravery or the manliness, but the outside gives a misleading impression. We should, then, emphasize virtue rather than pleasure.
Book XIV
If virtue leads, pleasure can still be had; but when pleasure leads, it is easy enough to lose sight of virtue, and not uncommonly pleasure as well.
Book XV
It is also not possible to hold that the highest good is some mix of pleasure and virtue, given that the two are not equally good; the highest good, to be highest, must take its essential character from its better part. Further, an alliance between unequal parts is a fairly shaky thing to hold the place of highest good. It would seem to split one's motivations among two masters. But goodness requires an integrity; "we are born into a kingdom; to obey the God is liberty."
Book XVI
Virtue, then, is true happiness. It requires that we do good and endure unshaken in it, and the reward it gives us is to make us like gods. The virtuous man is independent of fortune. Those who are still building virtue do require some help from fortune; but they are still more free than those who are not seeking virtue.
Book XVII
We should thus not be concerned with people who attack philosophy for hypocrisy. (There is clear indication in this and the following chapters that Seneca has in mind criticisms of himself for this ground.) A man may recognize the value of simplicity even if he has a fine estate; it is not to be expected that people should reach the end of the race all at once rather than through a process. It is the direction that matters. Seneca does not claim to be a Stoic sage; he is merely a man who understands the value of wisdom, and thus actively seeks it. But this is not valueless.
Book VIII
If the objector insists that this is a matter of talking one way and living another, however, Seneca argues that this would consistently require an attack on everyone -- not just Seneca, but Plato, Zeno, Epicurus. Human beings are such that they must improve; this means first recognizing our weaknesses and failings, and insisting that they are indeed weaknesses and failings that must be removed. This is what all good men do; some more swiftly than other, but we all, if we do well, speak the truth about virtue and vice despite not conforming to it perfectly -- this is the way in which human beings come to conform to it at all.
Book XIX
He gives the example of Diodorus the Epicurean, who committed suicide; people have argued that he did not follow the precepts of Epicurus, but Seneca defends him. In reality it is the critics who display the pathology, and Seneca is entirely dismissive of their attempts to pretend to high ground, in a rather interesting passage using a crucifixion metaphor:
You argue about the life and death of another, and yelp at the name of men whom some peculiarly noble quality has rendered great, just as tiny curs do at the approach of strangers: for it is to your interest that no one should appear to be good, as if virtue in another were a reproach to all your crimes. You enviously compare the glories of others with your own dirty actions, and do not understand how greatly to your disadvantage it is to venture to do so: for if they who follow after virtue be greedy, lustful, and fond of power, what must you be, who hate the very name of virtue? You say that no one acts up to his professions, or lives according to the standard which he sets up in his discourses: what wonder, seeing that the words which they speak are brave, gigantic, and able to weather all the storms which wreck mankind, whereas they themselves are struggling to tear themselves away from crosses into which each one of you is driving his own nail. Yet men who are crucified hang from one single pole, but these who punish themselves are divided between as many crosses as they have lusts, but yet are given to evil speaking, and are so magnificent in their contempt of the vices of others that I should suppose that they had none of their own, were it not that some criminals when on the gibbet spit upon the spectators.
(to be continued)