Meditations 4.29

If he is a stranger to the universe who does not know what is in it, no less is he a stranger who does not know what is going on in it. He is a runaway, who flies from social reason; he is blind, who shuts the eyes of understanding; he is poor, who has need of another, and has not from himself all things which are useful for life. He is an abscess on the universe who withdraws and separates himself from the reason of our common nature through being displeased with the things which happen, for the same nature produces this, and has produced thee too: he is a piece rent asunder from the state, who tears, his own soul from that of reasonable animals, which is one.

Marcus Aurelius, Meditations 4.29, translated by George Long

If he is an alien in the Universe who has no cognizance of the things that are in it, no less is he an alien who has no cognizance of what is happening in it. He is an exile, who exiles himself from civic reason; blind, he who will not see with the eyes of his understanding; a beggar, he who is dependent on another, and cannot draw from his own resources all that his life requires; an imposthume on the Universe, he who renounces, and severs himself from, the reason of our common Nature, because he is ill pleased at what happens—for the same Nature brings this into being, that also brought thee; a limb cut off from the community, he who cuts off his own soul from the soul of all rational things, which is but one.

Marcus Aurelius, Meditations 4.29, translated by C. R. Haines