it has nothing to do with "getting along".
for Aristotle you'll find a good treatment in Politics, book three. You can read it here
https://classics.mit.edu/Aristotle/politics.3.three.htmlIn book eight he says that citizens don't belong only to themselves, but belong to the state, because they are a part of it.
In the Nichomachean ethics he says "Therefore, the Good of man must be the end of the science of Politics. For even though it be the case that the Good is the same for the individual and for the state, nevertheless, the good of the state is manifestly a greater and more perfect good, both to attain and to preserve. To secure the good of one person only is better than nothing; but to secure the good of a nation or a state is a nobler and more divine achievement."
Aristotle's approach is that there is a kind of universal virtue for a man to be virtuous, but civic virtue depends on what the form of government you're in requires; for a republic it is the capacity to both rule and be ruled. Accordingly though, no matter what, the citizen prioritizes the regime's stability over their own individuality.
In other words, civic virtue is the capacity for putting the good of the state ahead of your own interest. Brutus, first consul of the Roman republic is the classic example.
I haven't read Rosseau, so i can't help you there, but i have read a whole mess of the founding fathers and public virtue was one of their favorite topics. and they absolutely said they were requirements.
Washington's farewell address has the great quote - "It is substantially true that virtue or morality is a necessary spring of popular government. The rule indeed extends with more or less force to every species
of free government. Who that is a sincere friend to it can look with indifference upon attempts to shake the foundation of the fabric?"
Madison said "I have observed, that gentlemen suppose, that the general legislature will do every mischief they possibly can, and that they will omit to do every thing good which they are authorized to do...But I go on this great republican principle, that the people will have virtue and intelligence to select men of virtue and wisdom. Is there no virtue among us? If there be not, we are in a wretched situation. No theoretical checks--no form of government can render us secure. To suppose that any form of government will secure liberty or happiness without any virtue in the people, is a chimerical idea. If there be sufficient virtue and intelligence in the community, it will be exercised in the selection of these men. So that we do not depend on their virtue, or put confidence in our rulers, but in the people who are to choose them."
Franklin said "Only a virtuous people are capable of freedom. As nations become corrupt and vicious, they have more need of masters."
Patrick Henry - "Bad men cannot make good citizens. It is when a people forget God that tyrants forge their chains. A vitiated state of morals, a corrupted public conscience, is incompatible with freedom. No free government, or the blessings of liberty, can be preserved to any people but by a firm adherence to justice, moderation, temperance, frugality, and virtue; and by a frequent recurrence to fundamental principles.
And of course, Adams notes: "Public virtue cannot exist in a Nation without private Virtue, and public Virtue is the only Foundation of Republics. There must be a positive Passion for the public good, the public Interest, Honor, Power, and Glory, established in the Minds of the People, or there can be no Republican Government, nor any real Liberty. And this public Passion must be Superior to all private Passions.
Men must be ready, they must pride themselves, and be happy to sacrifice their private Pleasures, Passions, and Interests, nay their private Friendships and dearest Connections, when they Stand in Competition with the Rights of society."
if you want to hear that as admonishment, ok - be admonished. I prefer to read that and be inspired to be a better citizen.