An excellent letter! There is lots to learn and think about in this letter.
He spends the the first part discussing the differences between real pleasure and real joy. We humans often twist the meaning of words, until the original meaning is lost. This seems to be the case with pleasure and joy.
we Stoics hold that pleasure is a vice. Very likely it is a vice; but we are accustomed to use the word when we wish to indicate a happy state of mind.
The first lesson or reminder - pleasure is a vice. If you need Stoic toughening, this is where to begin: by attacking areas in your life where there is indulgent pleasure. Why else do some hug cold statues or take cold showers or sleep on the floor? They do it to show that these things are nothing to fear. We may fear poverty because we take pleasure in living richly. Therefore, you should live like a pauper for some time to show yourself that it is nothing to fear - that you can live in any circumstance and still be good. Therefore, if you find areas in your life where there is real pleasure, there may be some work and practice in that area.
Joy is lasting; it is "an elation of spirit, – of a spirit which trusts in the goodness and truth of its own possessions."
He then gives Lucilius some feedback on his writing, which I find interesting.
You have your words under control. You are not carried away by your language ... all your words are compact, and suited to the subject. You say all that you wish, and you mean still more than you say. This is a proof of the importance of your subject matter, showing that your mind, as well as your words, contains nothing superfluous or bombastic.
Many of us suffer from long-windedness or rambling. This may be a symptom of a disordered mind. We should pay attention to our thoughts and we should give particular focus to our inner dialogue. Then, when you have need to write or speak, you will have control over your thoughts. Make your point - keep it "compact" and "suited to the subject." Too many tangents and your point is lost in the jumble. Strive to rid the excess ... "nothing superfluous or bombastic."
He further improves this point that a well ordered and attentive mind is always ready for whatever comes, by comparing it to an army.
One of his similes appealed especially to me, that of an army marching in hollow square, in a place where the enemy might be expected to appear from any quarter, ready for battle. "This," said he, "is just what the wise man ought to do; he should have all his fighting qualities deployed on every side, so that wherever the attack threatens, there his supports may be ready to hand and may obey the captain's command without confusion."
Marcus Aurelius also used an analogy about being in an alert and ready state of mind.
The model for the application of your principles is the boxer rather than the gladiator. The gladiator puts down or takes up the sword he uses, but the boxer always has his hands and needs only to clench them into fists (Meditations 12.9).
the wise man is fortified against all inroads; he is alert; he will not retreat before the attack of poverty, or of sorrow, or of disgrace, or of pain. He will walk undaunted both against them and among them.
We human beings are fettered and weakened by many vices; we have wallowed in them for a long time, and it is hard for us to be cleansed. We are not merely defiled; we are dyed by them. But, to refrain from passing from one figure to another, I will raise this question, which I often consider in my own heart: why is it that folly holds us with such an insistent grasp? It is, primarily, because we do not combat it strongly enough, because we do not struggle towards salvation with all our might; secondly, because we do not put sufficient trust in the discoveries of the wise, and do not drink in their words with open hearts; we approach this great problem in too trifling a spirit.
- we don't fight them hard enough
- we minimize or hand-wave the words of the wise; we are complacent
You call me a man of sense, but I understand how many of the things which I crave are useless, and how many of the things which I desire will do me harm. I have not even the knowledge, which satiety teaches to animals, of what should be the measure of my food or my drink. I do not yet know how much I can hold.
The wise man is joyful, happy and calm, unshaken; he lives on a plane with the gods. Now go, question yourself; if you are never downcast, if your mind is not harassed by any apprehension, through anticipation of what is to come, if day and night your soul keeps on its even and unswerving course, upright and content with itself
Reflect, therefore, on this, that the effect of wisdom is a joy that is unbroken and continuous. The mind of the wise man is like the ultra-lunar firmament; eternal calm pervades that region. You have, then, a reason for wishing to be wise, if the wise man is never deprived of joy. This joy springs only from the knowledge that you possess the virtues. None but the brave, the just, the self-restrained, can rejoice.