“It is the nature of man to rise to greatness if greatness is expected of him.”

Letter to Harrison Blake (20 May 1860); published in Familiar Letters (1865)
Context: Men and boys are learning all kinds of trades but how to make men of themselves. They learn to make houses; but they are not so well housed, they are not so contented in their houses, as the woodchucks in their holes. What is the use of a house if you haven't got a tolerable planet to put it on? — If you cannot tolerate the planet that it is on? Grade the ground first. If a man believes and expects great things of himself, it makes no odds where you put him, or what you show him … he will be surrounded by grandeur. He is in the condition of a healthy and hungry man, who says to himself, — How sweet this crust is!

Journal entry (29 October 1838)

1840s, Heroes and Hero-Worship (1840), The Hero as Man of Letters

Source: The Friends of Voltaire (1906), Ch. 2 : Diderot : The Talker, p. 61

Rome, or Reason? A Reply to Cardinal Manning. Part I. The North American Review (1888)
Context: As a rule, an individual is egotistic in the proportion that he lacks intelligence. The same is true of nations and races. The barbarian is egotistic enough to suppose that an Infinite Being is constantly doing something, or failing to do something, on his account. But as man rises in the scale of civilization, as he becomes really great, he comes to the conclusion that nothing in Nature happens on his account—that he is hardly great enough to disturb the motions of the planets.

"The Colour of Life" in The Colour of Life and Other Essays on Things Seen and Heard (London: John Lane, 1896), p. 4.

As quoted in The Baptist Herald and Friend of Africa (October 1842) and "The Missionary Herald" in The Baptist Magazine Vol. 35 (January 1843), p. 41