“he who voluntarily confronts tremendous odds must have very great internal resources to draw upon.”
Book II, 2.89-[6].
History of the Peloponnesian War, Book II
Help us to complete the source, original and additional information
Thucydides 76
Greek historian and Athenian generalRelated quotes

Source: Creative Convergence, p.20., Science-Religion Dialog

"Whether Genius is Conscious of its Powers?"
The Plain Speaker (1826)

“Life, not death, is the great mystery you must confront.”
Source: The Final Testament of the Holy Bible

We gratefully acknowledge, as signal instances of the Divine favour towards us, that his Providence would not permit us to be called into this severe controversy, until we were grown up to our present strength, had been previously exercised in warlike operation, and possessed of the means of defending ourselves. With hearts fortified with these animating reflections, we most solemnly, before God and the world, declare that, exerting the utmost energy of those powers, which our beneficent Creator hath graciously bestowed upon us, the arms we have been compelled by our enemies to assume, we will, in defiance of every hazard, with unabating firmness and perseverence, employ for the preservation of our liberties; being with one mind resolved to die freemen rather than to live slaves.
Declaration of the Causes and Necessity of Taking Up Arms (1775); Jefferson composed the first draft of this document, but the final work was done by John Dickinson, working with his original draft. Full text online http://www.nationalcenter.org/1775DeclarationofArms.html
1770s

“He draws upon his subconscious mind.”
Thomas Edison, as quoted in The Living Age, Vol. 312 (1922), p. 742

Statement on Signing the Securities Bill http://www.presidency.ucsb.edu/ws/index.php?pid=14654 (27 May 1933)
1930s