Aubrey Stewart

The invulnerable is not that which is never struck, but that which is never wounded.

let us distinguish between injury and insult. The former is naturally the more grievous, the latter less important, and grievous only to the thin-skinned, since it angers men but does not wound them. Yet such is the weakness of men's minds, that many think that there is nothing more bitter than insult;

Only the bad attempt to injure the good. Good men are at peace among themselves; bad ones are equally mischievous to the good and to one another. If a man cannot be hurt by one weaker than himself, and a bad man be weaker than a good one, and the good have no injury to dread, except from one unlike themselves; then, no injury takes effect upon the wise man; f