Such was the end of these men; they were worthy of Athens, and the living need not desire to have a more heroic spirit, although they may pray for a less fatal issue. The value of such a spirit is not to be expressed in words. Any one can discourse to you for ever about the advantages of a brave defence, which you know already. But instead of listening to him I would have you day by day fix your eyes upon the greatness of Athens, until you become filled with the love of her; and when you are impressed by the spectacle of her glory, reflect that this empire has been acquired by men who knew their duty and had the courage to do it, who in the hour of conflict had the fear of dishonour always present to them, and who, if ever they failed in an enterprise, would not allow their virtues to be lost to their country, but freely gave their lives to her as the fairest offering which they could present at her feast.  The sacrifice which they collectively made was individually repaid to them; for they received again each one for himself a praise which grows not old, and the noblest of all sepulchers—I speak not of that in which their remains are laid, but of that in which their glory survives, and is proclaimed always and on every fitting occasion both in word and deed.  For the whole earth is the sepulchre of famous men; not only are they commemorated by columns and inscriptions in their own country, but in foreign lands there dwells also an unwritten memorial of them, graven not on stone but in the hearts of men.  Make them your examples, and, esteeming courage to be freedom and freedom to be happiness, do not weigh too nicely the perils of war.  The unfortunate who has no hope of a change for the better has less reason to throw away his life than the prosperous who, if he survive, is always liable to a change for the worse, and to whom any accidental fall makes the most serious difference.  To a man of spirit, cowardice and disaster coming together are far more bitter than death striking him unperceived at a time when he is full of courage and animated by the general hope.
Tucídides, História da Guerra do Peloponeso, Livro II, §43. Benjamin Jowett (trad.)