“The greatness of a mind is determined by the depth of its suffering.”

Source: The Grand Chessboard (1997), Chapter 2, The Eurasian Chessboard, p. 35.

Widely attributed since the mid to late 19th century, this apparently derives from a gloss or commentary on the following passage from Aristotle's Nicomachean Ethics (c. 325 BC), Book 1, Ch. XI (Bekker No. 1100b.13–14):
ὅμως δὲ καὶ ἐν τούτοις διαλάμπει τὸ καλόν, ἐπειδὰν φέρῃ τις εὐκόλως πολλὰς καὶ μεγάλας ἀτυχίας, μὴ δι᾽ ἀναλγησίαν, ἀλλὰ γεννάδας ὢν καὶ μεγαλόψυχος. εἰ δ᾽ εἰσὶν αἱ ἐνέργειαι κύριαι τῆς ζωῆς, καθάπερ εἴπομεν, οὐδεὶς ἂν γένοιτο τῶν μακαρίων ἄθλιος
But nevertheless, even in these [misfortunes], nobility of the soul is conspicuous, when a man bears and digests many and great misfortunes, not from insensibility, but because he is high spirited and magnanimous. But if the energies are the things that constitute the bliss or the misery of life, as we said, no happy man can ever become miserable.
A New Translation of the Nicomachean Ethics of Aristotle (1835), 3rd. ed., Oxford: J. Vincent. p. 30
Nevertheless even under these [misfortunes] the force of nobility shines out, when a man bears calmly many great disasters, not from insensibility, but because he is generous and of a great soul. Setting happiness then, as we do, not in the outward surroundings of man, but in his inward state, we may fairly say that no one who has attained to the bliss of virtue will ever justly become an object of pity or contempt.
St. George William Joseph Stock, Lectures in the Lyceum or Aristotle's ethics for English readers (1897), p. 47
Misattributed

Source: Love in the Time of Cholera

Source: Gift from the Sea (1955)
Context: The shape of my life is, of course, determined by many other things; my background and childhood, my mind and its education, my conscience and its pressures, my heart and its desires. I want to give and take from my children and husband, to share with friends and community, to carry out my obligations to man and to the world, as a woman, as an artist, as a citizen.
But I want first of all — in fact, as an end to these other desires — to be at peace with myself. I want a singleness of eye, a purity of intention, a central core to my life that will enable me to carry out these obligations and activities as well as I can. I want, in fact — to borrow from the languages of the saints — to live "in grace" as much of the time as possible. I am not using this term in a strictly theological sense. By grace I mean an inner harmony, essentially spiritual, which can be translated into outward harmony.
Context: The shape of my life today starts with a family. I have a husband, five children and a home just beyond the suburbs of New York. I have also a craft, writing, and therefore work I want to pursue. The shape of my life is, of course, determined by many other things; my background and childhood, my mind and its education, my conscience and its pressures, my heart and its desires. I want to give and take from my children and husband, to share with friends and community, to carry out my obligations to man and to the world, as a woman, as an artist, as a citizen.
But I want first of all — in fact, as an end to these other desires — to be at peace with myself. I want a singleness of eye, a purity of intention, a central core to my life that will enable me to carry out these obligations and activities as well as I can. I want, in fact — to borrow from the languages of the saints — to live "in grace" as much of the time as possible. I am not using this term in a strictly theological sense. By grace I mean an inner harmony, essentially spiritual, which can be translated into outward harmony. I am seeking perhaps what Socrates asked for in the prayer from Phaedrus when he said, "May the outward and the inward man be at one." I would like to achieve a state of inner spiritual grace from which I could function and give as I was meant to in the eye of God.

The Truth: An Uncomfortable Book About Relationships (2015)

1940 - 1948, Intimate Banalities' (1941)

Livejournal post http://james-nicoll.livejournal.com/176181.html (2005)
2000s

Quote in Delaunay's text 'Simultanism', October 1913; as cited in Futurism, ed. by Didier Ottinger; Centre Pompidou / 5 Continents Editions, Milan, 2008, p. 57
1910 - 1915

Speech at the Albert Hall (4 December 1924), quoted in On England, and Other Addresses (1926), pp. 70-71.
1924
Context: It is a testing time for democracy... Democracy, democratic government, calls for harder work, for higher education, for further vision than any form of government known in this world. It has not lasted long yet in the West, and it is only by those like ourselves who believe in it making it a success that we can hope to see it permanent and yielding those fruits which it ought to yield. The assertion of people's rights has never yet provided that people with bread. The performance of their duties, and that alone, can lead to the successful issue of those experiments in government which we have carried further than any other people in this world. Democracy can rise to great heights; it can also sink to great depths. It is for us so to conduct ourselves, and so to educate our own people, that we may achieve the heights and avoid the depths.