“The happiness and misery of men depend no less on temper than fortune.”

1860s, A Liberal Education and Where to Find It (1868)
Context: The life, the fortune, and the happiness of every one of us, and, more or less, of those who are connected with us, do depend upon our knowing something of the rules of a game infinitely more difficult and complicated than chess. It is a game which has been played for untold ages, every man and woman of us being one of the two players in a game of his or her own. The chessboard is the world, the pieces are the phenomena of the universe, the rules of the game are what we call the laws of Nature. The player on the other side is hidden from us. We know that his play is always fair, just, and patient. But also we know, to our cost, that he never overlooks a mistake, or makes the smallest allowance for ignorance. To the man who plays well, the highest stakes are paid, with that sort of overflowing generosity with which the strong shows delight in strength. And one who plays ill is checkmated — without haste, but without remorse.

Notes
Queen Mab (1813)

Source: Table Talk (1782), Line 246.

Source: Lovingkindness: The Revolutionary Art of Happiness

Source: The Real and the Unreal (1961) by Bill Davidson, p. 174

Canto V, lines 121–123 (tr. Longfellow).
The Divine Comedy (c. 1308–1321), Inferno

Inferno, canto v, line 121.
Bartlett's Familiar Quotations, 10th ed. (1919)

Brutus, Act IV, scene iii.
Source: Julius Caesar (1599)

No. 146.
The Tatler (1711–1714)