I say, then, that such a wise man is invulnerable against all injury; it matters not, therefore, how many darts be hurled at him, since he can be pierced by none of them. Just as the hardness of some stones is impervious to steel, and adamant can neither be cut, broken, or ground, but blunts all instruments used upon it; just as some things cannot be destroyed by fire, but when encircled by flame still retain their hardness and shape; just as some tall projecting cliffs break the waves of the sea, and though lashed by them through many centuries, yet show no traces of their rage; even so the mind of the wise man is firm, and gathers so much strength, that it is as safe from injury as any of those things which I have mentioned.