Courage is a mean with regard to fear and confidence.
(Aristotle (384-323 B.C.), Greek philosopher. Nicomachean Ethics 3.6; 1115a6-7, trans. by Ross-Urmson, The Complete Works of Aristotle, ed. Jonathan Barnes, Princeton, Princeton University Press (1985).)
Even the bravest among us rarely possesses the courage for what he really knows.
(Friedrich Nietzsche (1844-1900), German philosopher, classical scholar, critic of culture. Friedrich Nietzsche, Sämtliche Werke: Kritische Studienausgabe, vol. 6, p. 59, eds. Giorgio Colli and Mazzino Montinari, Berlin, de Gruyter (1980). Twilight of the Idols, "Maxims and Arrows," section 2 (prepared for publication 1888, published 1889).)