Seneca begins his twentieth letter to his friend Lucilius by asking him to prove his words by way of his actions, testing his progress as a student of Stoicism by in terms of what he does, rather than merely what he writes. It is a stark reminder that Stoicism is a practical philosophy, meant to actually be deployed daily during your life, not simply contemplated for a few hours a week, when we may be leisurely reading a book.
Seneca says that we should strive to keep “deed and word” in agreement with each other, but also immediately acknowledges that this is a high standard, difficult to maintain. (Yes, he knew something of that sort of difficulty from first person experience.) He goes on by commenting on specific examples:
“Observe yourself, then, and see whether your dress and your house are inconsistent, whether you treat yourself lavishly and your family meanly, whether you eat frugal dinners and yet build luxurious houses. You should lay hold, once for all, upon a single norm to live by, and should regulate your whole life according to this norm.” (XX.3)
Why do people behave incoherently, then? According to Seneca, this is the result of two problems. The first one being that too many people are simply not bothered by the inconsistencies between their actions and their words, i.e., they don’t take the pursuit of virtue at heart. The second one is that, even if some people are so bothered, they too easily slip back into old habits, out of lack of wisdom. In a sense, many of us simply don’t take our life seriously enough, conducting it as if we were in a game, where we make up our mind about what to do on the spur of the moment, without a compass to guide us through.
Seneca imagines Lucilius objecting that he has a large household to take care of, and that he therefore needs a lot of money. That may be the case, says the philosopher, but his dependents will support themselves if he stops indulging them, going on to suggest that one advantage of poverty (or at least of modest means) is that it immediately reveals who your true friends are: those sticking around even when there is little material advantage to be gained.
This is also one of those early letters in which Seneca is unabashed of quoting Epicurus, going into enemy camp, as he puts it at one point, not as a traitor, but as a scout, returning home with whatever he found of value, like this advice from the famous rival, who sounds almost like a Cynic:
“Believe me, your words will be more imposing if you sleep on a cot and wear rags. For in that case you will not be merely saying them; you will be demonstrating their truth.” (XX.9)
Interestingly, however, Seneca then engages in a short imaginary dialogue with Epicurus where he points out that the rags ought to be worn by choice, not necessity, or it is going to be difficult to determine whether the person in question is truly virtuous or simply unlucky.
This line of reasoning leads Seneca to suggest to his friend the standard Stoic exercise of mild self-deprivation:
“I hold it essential, therefore, to do as I have told you in a letter that great men have often done: to reserve a few days in which we may prepare ourselves for real poverty by means of fancied poverty. … Let the soul be roused from its sleep and be prodded, and let it be reminded that nature has prescribed very little for us.“ (XX.13)
This is one of my own regular practices, which can take the form of a cold shower (to remind myself of just how good it is to be able to take hot ones), a day or two of fasting (to better enjoy the next meal), a week or so of not buying anything other than food (who the hell needs all that stuff that corporations are trying to sell us anyway?), or a brisk walk in the cold while being underdressed (to appreciate how lucky I am to have a coat). Deprivation exercises, then, have multiple functions: they test our endurance, they prepare us for possible adversity, they remind us that a lot of things we think we need are not really necessary, and they reset our hedonic threadmill, making us appreciate what we have all over again.