De Virtutibus

In order, therefore, that the affairs of his own people may not be injured by the cowardice of those who go forth to battle, while the enemy obtains success and glory, slaying those cowardly foes with great contempt, and being also aware that an inactive irresolute coward was of no use at all, but was rather a hindrance to success, the lawgiver removed from the army all those who were devoid of boldness, and those who were inclined to faint or shrink out of cowardice, just as I

And cowardice is a disease, and a worse one, too, than any of those which affect the body, inasmuch as it destroys the faculties of the soul; for diseases of the body, indeed, are at their height but for a short period, but cowardice is an evil which grows with the man in a greater degree, or, at all events, not less than the parts of the body which are united to it, cleaving to the soul from its earliest infancy to the very extremity of old age, unless God himself interpose to cure it; for all things are possible to God.

And, moreover, the lawgiver does not summon even all the men of impetuous courage, not even although they are full of strength and energy, both in soul and body, and eager to be the foremost in the conflict and in the encountering of danger; but, having praised them for their good will, because they display a disposition willing to share in the dangers of their countrymen, and eager, and void of fear, he proceeds to inquire whether they are entangled in any important circumstances which have a strong influential power of attraction.