1.Courage is a mean with regard to fear and confidence. 
Aristotle, Nicomachean Ethics 3.6 (1094 A.D.)
2.Courage is a quality so necessary for maintaining virtue, that it is always respected, even when it is associated with vice. 
Samuel Johnson, Quoted in James Boswell, Life of Samuel Johnson, June 11, 1784 (1791)
3.Courage is almost a contradiction in terms. It means a strong desire to live taking the form of a readiness to die. 
G.K. Chesterton, Orthodoxy, ch. 6 (1909)