“It is not reasonable that he who does not shoot should hit the mark, nor that he who does not stand fast at his post should win the day, or that the helpless man should succeed or the coward prosper.”

Diogenes of Sinope, as quoted in Pearls of Thought (1882), edited by Maturin Murray Ballou, p. 22
Misattributed

Source: Norwegian Wood

Source: Hilkhot De'ot (Laws Concerning Character Traits), Chapter 5, Section 13

Source: Trachiniae, Line 296.

Note to Stanza 29 part 4
Spiritual Canticle of The Soul and The Bridegroom, Notes to the Stanzas

Alternate version: He who knows the truth and does not speak it truly is a miserable creature.
Quoted in "Julius Streicher" - Page 211 - By Randall L. Bytwerk

Martí : Thoughts/Pensamientos (1994)

Arrowsmith (1925)
Context: Perhaps I am a crank, Martin. There are many who hate me. There are plots against me—oh, you t'ink I imagine it, but you shall see! I make many mistakes. But one thing I keep always pure: the religion of a scientist.
To be a scientist—it is not just a different job, so that a man should choose between being a scientist and being an explorer or a bond-salesman or a physician or a king or a farmer. It is a tangle of ver-y obscure emotions, like mysticism, or wanting to write poetry; it makes its victim all different from the good normal man. The normal man, he does not care much what he does except that he should eat and sleep and make love. But the scientist is intensely religious—he is so religious that he will not accept quarter-truths, because they are an insult to his faith.
He wants that everything should be subject to inexorable laws. He is equal opposed to the capitalists who t'ink their silly money-grabbing is a system, and to liberals who t'ink man is not a fighting animal; he takes both the American booster and the European aristocrat, and he ignores all their blithering. Ignores it! All of it! He hates the preachers who talk their fables, but he iss not too kindly to the anthropologists and historians who can only make guesses, yet they have the nerf to call themselves scientists! Oh, yes, he is a man that all nice good-natured people should naturally hate! ~ Gottlieb, Ch. 26

Walden (1854)
Context: A living dog is better than a dead lion. Shall a man go and hang himself because he belongs to the race of pygmies, and not be the biggest pygmy that he can? Let every one mind his own business, and endeavor to be what he was made. Why should we be in such desperate haste to succeed, and in such desperate enterprises? If a man does not keep pace with his companions, perhaps it is because he hears a different drummer. Let him step to the music which he hears, however measured or far away.<!--pp.366-367