“I think a man cannot strive wholeheartedly with an enemy unless he have much in common with him, and as the strife goes on he gets liker.”

From a letter to Harold Preece (c. June 1928)
Letters

Source: Erewhon (1872), Ch. 19

Source: The Royal Tenenbaums

Source: The Gospel of Sri Ramakrishna (1942), p. 385
Context: The waves belong to the Ganges, not the Ganges to the waves. A man cannot realize God unless he gets rid of all such egotistic ideas as "I am such an important man" or "I am so and so". Level the mound of "I" to the ground by dissolving it with tears of devotion.

1840s, Heroes and Hero-Worship (1840), The Hero As King

Source: Dictionary of Burning Words of Brilliant Writers (1895), P. 208.

Chap. VII: Noble Life And Common Life, Or Effort And Inertia
The Revolt of the Masses (1929)
Context: The mass-man would never have accepted authority external to himself had not his surroundings violently forced him to do so. As to-day, his surroundings do not so force him, the everlasting mass-man, true to his character, ceases to appeal to other authority and feels himself lord of his own existence. On the contrary the select man, the excellent man is urged, by interior necessity, to appeal from himself to some standard beyond himself, superior to himself, whose service he freely accepts.… Contrary to what is usually thought, it is the man of excellence, and not the common man who lives in essential servitude. Life has no savour for him unless he makes it consist in service to something transcendental. Hence he does not look upon the necessity of serving as an oppression. When, by chance, such necessity is lacking, he grows restless and invents some new standard, more difficult, more exigent, with which to coerce himself. This is life lived as a discipline — the noble life.

Variant: Similarly on pg. 136: "About this getting rich in politics. Like I said, you just can't do it unless you're a crook." And earlier: "An honest public servant can't become rich in politics." - Truman's diary, 24 April 1954.
Source: Harry S Truman, quoted in Plain Speaking: An Oral Biography of Harry S Truman by Merle Miller, 1973-1974 SBN 425-02664-7 LOC 73-87198, Berkeley Medallion Edition, October, 1974, Chapter 10. "The Only Defeat − and Then Victory", pg. 134.