“He knows his own strength; he knows that he was born to carry burdens.”
Epistulae Morales ad Lucilium (Moral Letters to Lucilius), Letter LXXI: On the supreme good
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Seneca the Younger 225
Roman Stoic philosopher, statesman, and dramatist -4–65 BCRelated quotes

Listen, Little Man! (1948)
Context: The Little Man does not know that he is little, and he is afraid of knowing it. He covers up his smallness and narrowness with illusions of strength and greatness, of others' strength and greatness. He is proud of his great generals but not proud of himself. He admires thought which he did not have and not the thought he did have. He believes in things all the more thoroughly the less he comprehends them, and does not believe in the correctness of those ideas which he comprehends most easily.
Charles Davis of the Big Ten Network, quoted at Ringer 23.com (undated)

Associated Press (December 16, 1999) "Christopher Walken Prefers His Ozzie Nelson Side", The Press of Atlantic City, p. B3.

Pupils at Sais (1799)
Context: Over his own heart and his own thoughts he watched attentively. He knew not whither his longing was carrying him. As he grew up, he wandered far and wide; viewed other lands, other seas, new atmospheres, new rocks, unknown plants, animals, men; descended into caverns, saw how in courses and varying strata the edifice of the Earth was completed, and fashioned clay into strange figures of rocks. By and by, he came to find everywhere objects already known, but wonderfully mingled, united; and thus often extraordinary things came to shape in him. He soon became aware of combinations in all, of conjunctures, concurrences. Erelong, he no more saw anything alone. — In great variegated images, the perceptions of his senses crowded round him; he heard, saw, touched and thought at once. He rejoiced to bring strangers together. Now the stars were men, now men were stars, the stones animals, the clouds plants; he sported with powers and appearances; he knew where and how this and that was to be found, to be brought into action; and so himself struck over the strings, for tones and touches of his own.

On LBJ (June 3, 1967); quoted in "The World Turned Upside Down" http://archives.chicagotribune.com/1968/03/25/page/20/article/the-world-turned-upside-down

“He who stands upon his own strength will never stand.”
Source: Quotes from secondary sources, Dictionary of Burning Words of Brilliant Writers, 1895, P. 531.

Book I, Canto III, II Love a Virtue.
The Angel In The House (1854)

Source: A Heap o' Livin' (1916), When You Know a Fellow, stanza 1, p. 12.