“The greatest contribution of a leader is to make other leaders.”

Source: The Heritage Universe, Resurgence (2002), Chapter 16, “And Then There Were None” (p. 187)

Source: 1930s, Patterns of aggressive behavior in experimentally created “social climates”, 1939, p. 272.

War Memoirs: Volume II (1938), p. 1887
War Memoirs

Source: My Share Of The Task (2013), p. 393-394
Context: All leaders are human. They get tired, angry, and jealous and carry the same range of emotions and frailties common to mankind. Most leaders periodically display them. The leaders I most admired were totally human but constantly strove to be the best humans they could be. Leaders make mistakes, and they are often costly. The first reflex is normally to deny the failure to themselves; the second is to hide it from others, because most leaders covet a reputation for infallibility. But it's a fool's dream and inherently dishonest. There are few secrets to leadership. It is mostly just hard work. More than anything else it requires self-discipline. Colorful, charismatic characters often fascinate people, even soldiers. But over time, effectiveness is what counts. Those who lead most successfully do so while looking out for their followers' welfare.

Al-Tirmidhi, Hadith 1011
Sunni Hadith

Thomas Jefferson, letter to John Dickinson (23 July 1801), published in The Works of Thomas Jefferson in Twelve Volumes http://oll.libertyfund.org/ToC/0054.php, Federal Edition, Paul Leicester Ford, ed., New York: G. P. Putnam's Sons, 1904, Vol. 9 http://files.libertyfund.org/files/757/0054-09_Bk.pdf, pp. 280-282.
1800s, First Presidential Administration (1801–1805)
Context: I am sorry the person recommended has not been agreeable to all the republicans, but I am more concerned to see in this disapprobation a germ of division which, if not smothered, will continue you under that rule from which union is relieving our fellow citizens in other states. It is disheartening to see, on the approaching crisis of election, a division of that description of Republicans, which has certainly no strength to spare. But, my dear friend, if we do not learn to sacrifice small differences of opinion, we can never act together. Every man cannot have his way in all things. If his own opinion prevails at some times, he should acquiesce on seeing that of others preponderate at others. Without this mutual disposition we are disjointed individuals, but not a society. My position is painful enough between federalists who cry out on the first touch of their monopoly, and republicans who clamor for universal removal. A subdivision of the latter will increase the perplexity. I am proceeding with deliberation and inquiry to do what I think just to both descriptions and conciliatory to both. The greatest good we can do our country is to heal it’s party divisions & make them one people. I do not speak of their leaders who are incurable, but of the honest and well-intentioned body of the people. I consider the pure federalist as a republican who would prefer a somewhat stronger executive; and the republican as one more willing to trust the legislature as a broader representation of the people, and a safer deposit of power for many reasons. But both sects are republican, entitled to the confidence of their fellow citizens. Not so their quondam leaders, covering under the mask of federalism hearts devoted to monarchy. The Hamiltonians, the Essex-men http://www.monticello.org/mulberry-row/people/essex, the revolutionary tories &c. They have a right to tolerance, but neither to confidence nor power. It is very important that the pure federalist and republican should see in the opinion of each other but a shade of his own, which by a union of action will be lessened by one-half: that they should see & fear the monarchist as their common enemy, on whom they should keep their eyes, but keep off their hands.