Human nature, according to Stoic philosophers, is not only rational but social.
From Meditations by Marcus Aurelius
We are social beings
You participate in society by your existence. Then participate in its life through your actions — all your actions. Any action not directed toward a social end (directly or indirectly) is a disturbance to your life, an obstacle to wholeness, a source of dissension — like the man acting as a faction unto himself, out of step with the majority (9.23).
In a sense, people are our proper occupation. Our job is to do them good and put up with them. But when they obstruct our proper tasks they become indifferent to us — like sun, wind, or animals. They impede our actions, but they can’t impede our intentions or our dispositions because we can accommodate and adapt. The mind adapts its purposes to the obstacle, and what stands in the way becomes the way (5.20).
People exist for one another. You can instruct or endure them (8.59).
Wash yourself clean with simplicity, humility, and indifference to everything but right and wrong. Care for other human beings. Follow God (7.31).
Don’t turn away from others
To move from one unselfish action to another with God in mind. Only there is delight and stillness (6.7).
When you wake up in the morning, tell yourself: The people I deal with today will be meddling, ungrateful, arrogant, dishonest, jealous, and surly. They are like this because they can’t tell good from evil. But I have seen the beauty of good, and the ugliness of evil, and have recognized that the wrongdoer has a nature related to my own. So none of them can hurt me. No one can implicate me in ugliness. Nor can I feel angry or hate them. We were born to work together like feet, hands, and eyes, like the two rows of teeth, upper and lower. To obstruct each other is unnatural. To feel anger at others, to turn your back on them: these are obstructions. (2.1).
People find pleasure in different ways. I find in in keeping my mind clear. In not turning away from people or the things that happen to them. In accepting and welcoming everything I see. In treating each thing as it deserves (8.43).
Kindness is its own reward
Some people, when they do someone a favor, are always looking for a chance to call it in. Some don’t, but they privately think they’re owed something. But others don’t even do that. They’re like a vine that produces grapes without looking for anything in return. They are a human being helping others (5.6).
You’re no different from anyone else
When you deal with irrational animals, or with things and circumstances, be generous and straightforward. You are rational, but they are not. When you deal with your fellow human beings, behave as one. They share reason with you. And invoke the gods regardless (6.23).
Practice really hearing what people say. Do your best to get inside their minds (6.53).
Speak the truth as you see it, but with kindness, humility, and without hypocrisy (8.5).
Take care that you don’t treat inhumanity as it treats human beings (7.65).
Be gentle with others
When you face people’s insults or hatred, look at their souls. Get inside them. Look at what sort of people they are. You’ll realize there’s no need to impress them. But you should still be kind to them. They are by nature your friends (9.27).
It’s cruel to forbid people from striving for what they think is good for them. And yet that’s just what you do when you get angry at their misbehavior. Are they drawn toward what they think is good for them even though it’s not good for them? Then show them that. Prove it to them instead of losing your temper (6.27).
If they’ve made a mistake, correct them gently and show them where they went wrong. If you can’t do that, then the blame lies with you. Or no one (10.4).
Kindness is invincible
Kindness is invincible, provided it’s sincere. What can even the most vicious person do if you keep treating him with kindness and gently set him straight (if you get the chance), correcting him cheerfully at the exact moment that he’s trying to do you harm. Show him, gently and without pointing fingers, that it’s so. Don’t do it sardonically or meanly, but affectionately — with no hatred in your heart. Speak directly even if there are other people around (11.18).
When you need encouragement, think of the qualities the people around you have: this one’s energy, that one’s modesty, another’s generosity, and so on. Nothing is as encouraging as when virtues are visibly embodied in the people around us, when we’re practically showered with them. It’s good to keep this in mind (6.48).
Reason & Virtue
I’ve shortened and arranged the quotations for readability. Quotations are from Gregory Hays translation published by Modern Library, a translation by Francis Hutcheson and James Moor and published by the Liberty Fund, Inc, and the Penguin Classics translated by Martin Hammond.