The history of the world shows us that men are not to be counted by their numbers, but by the fire and vigour of their passions; by their deep sense of injury; by their memory of past glory; by their eagerness for fresh fame; by their clear and steady resolution of ceasing to live, or of achieving a particular object, which, when it is once formed, strikes off a load of manacles and chains, and gives free space to all heavenly and heroic feelings. All great and extraordinary actions come from the heart.

Sydney Smith (1771–1845) English clergyman, essayist, wit

Lecture (1804-1806), Moral Philosophy, No. 27 “On Habit, Part 2,” Royal Institution, London
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Collected in his Elementary Sketches of Moral Philosophy (1849).

Quoted by Theodore Roosevelt in his speech (1901-09-05), "Brotherhood and the Heroic Virtues," Grand Army of the Republic Veterans Reunion, Burlington, Vermont, collected in Roosevelt's The Strenuous LIfe (1902).