“I do not admire the excess of a virtue as of valour, except I see at the same time the excess of the opposite virtue, as in Epaminondas, who had the greatest valour and the greatest kindness. For otherwise it is not to rise, it is to fall. We do not display greatness by going to one extreme, but in touching both at once, and filling all the intervening space.”

“The brutes do not admire each other. A horse does not admire his companion. Not that there is no rivalry between them in a race, but that is of no consequence; for, when in the stable, the heaviest and most ill-formed does not give up his oats to another as men would have others do to them. Their virtue is satisfied with itself.”

“When I consider the small span of my life absorbed in the eternity of all time, or the small part of space which I can touch or see engulfed by the infinite immensity of spaces that I know not and that know me not, I am frightened and astonished to see myself here instead of there … now instead of then.”

“The power of a man's virtue should not be measured by his special efforts, but by his ordinary doing.”

“Reverend Fathers, my letters do not customarily follow one another so closely, nor are they usually so extensive. The little time I have had has caused both. I have made this one longer only because I have not had the leisure of making it shorter.”

“We naturally believe we are more capable of reaching the centre of things than of embracing their circumference, and the visible extent of the world is visibly greater than we. But since we in our turn are greater than small things, we think we are more capable of mastering them, and yet it takes no less capacity to reach nothingness than the whole. In either case it takes an infinite capacity, and it seems to me that anyone who had understood the ultimate principles of things might also succeed in knowing infinity. One depends on the other, and one leads to the other. These extremes touch and join by going in opposite directions, and they meet in God and God alone.”

“Extreme intelligence is accused of being as foolish as extreme lack of it; only moderation is good. The majority have laid this down and attack anyone who deviates from it towards any extreme whatever. I am not going to be awkward, I readily consent to being put in the middle and refuse to be at the bottom end, not because it is the bottom but because it is the end, for I should refuse just as much to be put at the top. It is deserting humanity to desert the middle way. The greatness of the human soul lies in knowing how to keep this course; greatness does not mean going outside it, but rather keeping within it.”