The frenchman line does not occur in other editions of this essay. This is the only place i have seen it.

The essay itself is highly thought-provoking and an evisceration of Mankind. I especially like his indictment of "Moral Sense";

One is obliged to concede that in true loftiness of character, Man cannot claim to approach even the meanest of the Higher Animals. It is plain that he is constitutionally incapable of approaching that altitude; that he is constitutionally afflicted with a Defect which must make such approach forever impossible, for it is manifest that this defect is permanent in him, indestructible, ineradicable.

I find this Defect to be the Moral Sense. He is the only animal that has it. It is the secret of his degradation. It is the quality which enables him to do wrong. It has no other office. It is incapable of performing any other function. It could never have been intended to perform any other. Without it, man could do no wrong. He would rise at once to the level of the Higher Animals.

Since the Moral Sense has but the one office, the one capacity -- to enable man to do wrong – it is plainly without value to him. It is as valueless to him as is disease. In fact, it manifestly is a disease.

The Moral Sense enables a man to do wrong. It enables him to do wrong in a thousand ways. Rabies is an innocent disease, compared to the Moral Sense. No one, then, can be the better man for having the Moral Sense. What now, do we find the Primal Curse to have been? Plainly what it was in the beginning: the infliction upon man of the Moral Sense; the ability to distinguish good from evil; and with it, necessarily, the ability to do evil; for there can be no evil act without the presence of consciousness of it in the doer of it.

The point is that moral sense enables one to distinguish right from wrong and so when you do wrong to others you are fully conscious of the suffering it causes. And yet mankind does it in a thousand different ways.