The Basis of Morality by Part 3 Chapter 6 Page 40

with the accuser's blood. Now this obtains, not because the lie is wrong in itself, since, were such the reason, to accuse a man of an injury done by violence would certainly be regarded as equally outrageous, — which is not the case, as every one knows; but it is due to that principle of chivalry, which in reality bases right on might; so that whoever, when trying to work mischief, has recourse to falsehood, proves that he lacks either power, or the requisite courage.

Every untruth bears witness of his fear; and this is why a fatal verdict is passed on him.