(1) It is maintained that savage or uncultivated nations are not a fair criterion of mankind generally:  that as men become more civilized, they approximate to unity of moral sentiment; and what civilized men agree in, is alone to be taken as the judgment of the race.

Now, this argument would have great weight, in any discussion as to what is good, useful, expedient, or what is in accordance with the cultivated reason or intelligence of mankind; because civilization consists in the exercise of men’s intellectual faculties to improve their condition.  But in a controversy as to what is given us by nature,—­what we possess independently of intelligent search and experience,—­the appeal to civilization does not apply.  What civilized men agree upon among themselves, as opposed to savages, is likely to be the reverse of a natural instinct; in other words, something suggested by reason and experience.

In the next place, counting only civilized races, that is, including the chief European, American, and Asiatic peoples of the present day, and the Greeks and Romans of the ancient world, we still find disparities on what are deemed by us fundamental points of moral right and wrong.  Polygamy is regarded as right in Turkey, India, and China, and as wrong in England.  Marriages that we pronounce incestuous were legitimate in ancient times.  The views entertained by Plato and Aristotle as to the intercourse of the sexes are now looked upon with abhorrence.

(2) It has been replied that, although men differ greatly in what they consider right and wrong, they all agree in possessing some notion of right and wrong.  No people are entirely devoid of moral judgments.

But this is to surrender the only position of any real importance.  The simple and underived character of the moral faculty is maintained because of the superior authority attached to what is natural, as opposed to what is merely conventional.  But if nothing be natural but the mere fact of right and wrong, while all the details, which alone have any value, are settled by convention and custom, we are as much at sea on one system as on the other.

(3) It is fully admitted, being, indeed, impossible to deny, that education must concur with natural impulses in making up the moral sentiment.  No human being, abandoned entirely to native promptings, is ever found to manifest a sense of right and wrong.  As a general rule, the strength of the conscience depends on the care bestowed on its cultivation.  Although we have had to recognize primitive distinctions among men as to the readiness to take on moral training, still, the better the training, the stronger will be the conscientious determinations.

But this admission has the effect of reducing the part performed by nature to a small and uncertain amount.  Even if there were native preferences, they might be completely overborne and reversed by an assiduous education.  The difference made by inculcation is so great, that it practically amounts to everything.  A voice so feeble as to be overpowered by foreign elements would do no credit to nature.