The first part of the letter addresses some advice. Seneca seems to say that in some cases, more deliberation should be taken before giving out advice, because a hasty reply might exacerbate the problem.
since more deliberation is necessary in settling than in propounding a problem!
He then discusses how a true friend takes on his friend's problems.
I am not your friend unless whatever is at issue concerning you is my concern also. Friendship produces between us a partnership in all our interests.
And later he writes,
you must live for your neighbour, if you would live for yourself. This fellowship, maintained with scrupulous care, which makes us mingle as men with our fellow-men and holds that the human race have certain rights in common, is also of great help in cherishing the more intimate fellowship which is based on friendship, concerning which I began to speak above. For he that has much in common with a fellow-man will have all things in common with a friend.
For anyone who thinks a Stoic is a lone wolf who wants to disengage with people and society, they should consider the above passage from Seneca. Stoics are social; our ethics are based on the Hierocles Concentric Circles of Cosmopolitanism which focuses on concern and care for oneself and then for those nearest him, then next nearest to him, until he has care and concern for all those who live in the cosmos.
Seneca then gets into the "quibble" (defined as an evasion of or shift from the point or a minor objection or criticism) about the "subtle dialecticians." Seneca would prefer
those subtle dialecticians of yours advise me how I ought to help a friend, or how a fellow-man, rather than tell me in how many ways the word "friend" is used, and how many meanings the word "man" possesses.
In other words, the aim of dialectic is to advise the wise approach of action with regard to friends, rather than talking about the meaning of the word friend. As Epictetus teaches - show me, don't tell me; or embody your philosophy, don't merely talk of it. Seneca provides other examples of foolish syllogisms which waste time and energy.
The seriousness of the problems our friends and humanity face are not to be played with by such foolish syllogisms.
Would you really know what philosophy offers to humanity? Philosophy offers counsel. Death calls away one man, and poverty chafes another; a third is worried either by his neighbour's wealth or by his own. So-and-so is afraid of bad luck; another desires to get away from his own good fortune. Some are ill-treated by men, others by the gods. Why, then, do you frame for me such games as these? It is no occasion for jest; you are retained as counsel for unhappy mankind. You have promised to help those in peril by sea, those in captivity, the sick and the needy, and those whose heads are under the poised axe. Whither are you straying? What are you doing?
One feels the deep sense of obligation of trying to help others in distress and anxiety after reading the above passage. "You are retained as counsel for unhappy mankind." It is indeed a challenge to convince others that their fears, worries and anxieties stem from their own false value judgements.
Death is nothing to fear - we Stoics practice remembering our own deaths every day.
People wring their hands about poverty - we Stoics practice by living with little means and sleeping on the ground to prove that it is nothing to fear; we fast and eat little to know that we can survive living minimally.
Others stew over the possessions, homes, boats, cars, 401K accounts and vast sums of money our neighbors' have, while we have relatively little - we Stoics know that this is an indifferent to our moral well-being and that a life worth living does not depend on vast sums of wealth.
Some get depressed about their lot in life, thinking that they have bad luck - we Stoics know that we can take any obstacle and use it to prove our will and moral good is the only good.
Still others feel they are cuffed with golden chains or can never have a private moment from their political, managerial or famous roles - we Stoics know a good life can be lived in a palace or on a street.
Some people feel they are rebuffed, discriminated against or pushed aside by other people or by Fate - we Stoics know that much is out of our control and that the only thing in our control is our will to act nobly with courage, wisdom and justice; we know that injustice cannot be fixed with more injustice.
By embodying our philosophy we can help others remedy their ills. We can talk and show others there is a way out of the ills society largely brings on itself. Syllogisms will not help them.
Help him, and take the noose from about his neck. Men are stretching out imploring hands to you on all sides; lives ruined and in danger of ruin are begging for some assistance; men's hopes, men's resources, depend upon you. They ask that you deliver them from all their restlessness, that you reveal to them, scattered and wandering as they are, the clear light of truth. Tell them what nature has made necessary, and what superfluous; tell them how simple are the laws that she has laid down, how pleasant and unimpeded life is for those who follow these laws, but how bitter and perplexed it is for those who have put their trust in opinion rather than in nature.
This life does not have to be complex and technical. It can be made simple and clear. In sum, "Frankness, and simplicity beseem true goodness."