Fads, trends, populism, crowd favorites - I've tried to be leery of what the majority desires. If only the majority were in favor of justice for all, temperance, courage and wisdom, then perhaps I would willingly go along with the crowd. But usually what the crowd desires is not wise, but foolish. They will choose the well-worn, popular path. For this reason, I think, Seneca approves of the "impulse which prompted" Lucilius to "[tread under feet] that which is approved by the crowd.
The phrase "tread under feet" seems to mean to ignore, or oppress or put down. Therefore, Seneca approves of the idea of going against the crowd, as long as that means one is living philosophically.
He compares the desires of the crowd to a siren song. Odysseus had to plug the ears of his men so they would not hear the siren song, lest they succumbed to it and dash their ships into the rock. Similarly, we must plug our ears to the calls of the crowd, which are everywhere!
the song, however, which you have to fear, echoes round you not from a single headland, but from every quarter of the world. Sail, therefore, not past one region which you mistrust because of its treacherous delights, but past every city. Be deaf to those who love you most of all; they pray for bad things with good intentions. And, if you would be happy, entreat the gods that none of their fond desires for you may be brought to pass. What they wish to have heaped upon you are not really good things; there is only one good, the cause and the support of a happy life, – trust in oneself.
Seneca warns that we must be deaf even "to those who love you most all." What an odd thing to say. I presume that what he means is that those who love us most, may not have embraced philosophy, and therefore, when they pray for you, they are praying that you become famous, rich, handsome, healthy or some sort of indifferent. Or they may be praying that you don't die or become ill or fall on so-called misfortune. Therefore, Seneca says that if you really want to be happy, plead with the gods that your loved ones' prayers are not answered.
I'm not so sure how sound this advice from Seneca is. I'm not so sure a practicing Stoic would forbid his loved ones to pray for such things, nor would he go out of his way to pray to the gods to not answer the prayers of his loved ones. At best, a practicing Stoic may be completely nonplussed by such prayers and would not worry if those things came (or not) into his life. He would view them as indifferents regardless if they came (or not) due to prayers from a loved one or otherwise.
The next part of the letter delves into the subject of work; and I assume he means the subject of gainful employment. Work, itself, is an indifferent. Therefore, work can be infused with either virtue or vice. A practicing Stoic, then would attempt to make his work noble.
Make yourself happy through your own efforts; you can do this, if once you comprehend that whatever is blended with virtue is good, and that whatever is joined to vice is bad. Just as nothing gleams if it has no light blended with it, and nothing is black unless it contains darkness or draws to itself something of dimness, and as nothing is hot without the aid of fire, and nothing cold without air; so it is the association of virtue and vice that makes things honourable or base.
Knowledge of how to make good use of things (indifferents) is the art of philosophy. The good, therefore, is knowledge. And evil is lack of knowledge. Your human craft is to gain knowledge about how to be a good human.
Just as a carpenter learns to work with wood and there are varying degrees of craftsmanship in different carpenters due to knowledge and practice (as well as lack of knowledge and practice), so too we can apply this analogy to what it means to be a good human being. A good human will seek justice for all (not only justice for some, and not at the expense of others' justice). A good human being will be disciplined and temperate in eating, entertainment, learning and working. A good human being will demonstrate courage and honesty. A good human being learns and demonstrates wisdom. The medium for the carpenter is wood. The medium for a human being is work and life.
in order that virtue may be perfect, there should be an even temperament and a scheme of life that is consistent with itself throughout; and this result cannot be attained without knowledge of things, and without the art which enables us to understand things human and things divine. That is the greatest good. If you seize this good, you begin to be the associate of the gods, and not their suppliant.
The 'art' he refers to is philosophy. If we learn and practice this art, we become equal with the gods. It does not matter our lot in life, the choice we have is our response to our lot and circumstances in life. Is our soul worthy to the challenge? Will you take the path less travelled or will you follow the crowd?
The unique part of *you* has a choice, regardless of circumstances.
What we have to seek for, then, is that which does not each day pass more and more under the control of some power which cannot be withstood. And what is this? It is the soul, – but the soul that is upright, good, and great. What else could you call such a soul than a god dwelling as a guest in a human body? A soul like this may descend into a Roman knight just as well as into a freedman's son or a slave. For what is a Roman knight, or a freedman's son, or a slave? They are mere titles, born of ambition or of wrong. One may leap to heaven from the very slums. Only rise
"And mould thyself to kinship with thy God."