Now if the distinct origin of these tribes be admitted, — if we are to regard the Negro and Australian, not as our fellow-men, brethren of the same great family as ourselves, but as beings of an inferior order, — and if duties towards them were not contemplated, as we may in that case presume them not to have been, in any of the positive commands on which the morality of the Christian world is founded, our relations to those tribes will ap pear not to be very different from those which we might consider ourselves to hold towards the higher races of brutes. If such races be not men, then the golden rule, " Whatsoever ye would that men should do unto you, do ye even so unto them," is not applicable to our intercourse with them. We can scarcely imagine a Grotius or a Puffendorf, or any other great jurist, attempting to determine the jus Belli or pacis between ourselves and a tribe of orangs, who had just sense enough to pass for men, and began to be suspected of the cheat, — which is nearly the true character of the Negroes, if those are right who maintain the doctrines just alluded to. And we may go a step further, and assert that there is, in such a case, no moral principle which should prevent a hungry wanderer in Negroland or Australia from satisfying his appetite, by killing and eating the first native he might happen to meet.
Thus, then, the widest extremes of opinion, and the greatest diversity in those rules of conduct which are founded upon such opi nions, may exist among those who profess the most implicit reverence for the scriptural dic tum, that " God bath made of one blood all nations of men, for to dwell on all the face of the earth." For, whilst some include under the term "men," all the individuals grouped together by the naturalist under the genus homo, and regard this genus as consisting of but a single species, of which the several races are only to be ranked as varieties, others assert that this genus includes several species, which form a gradual transition from the highest and most cultivated races of mankind, to those degraded races, which (as they affirm) have more in common with the brutes ; the former alone being really entitled to the appellation men, whilst the latter should be called by some other name indicating their close affinity to chimpanzees and orangs. Thus we are thrown back upon scientific inquiry, as the only legitimate means of bringing this ques tion to an issue ; and such an inquiry can only be rightly pursued, when it is prosecuted upon the broadest possible basis, and is made to comprehend every kind of information which can be brought to bear upon it. Nothing can be easier than to bring together an ex parte collection of facts, which shall give to either doctrine,— that of the specific unity, or that of the specific diversity, of the human races, — an apparently fair claim to recep tion. But since both cannot be true, and since the question can only be decided by the balance of probabilities, no evidentiary fact having any relation to the subject ought, to be left out of view ; and thus the science of Ethnology must be built upon the foundation afforded by numerous other departments of scientific inquiry. The anatomist examines the configuration of the body, and compares the peculiarities of the various tribes, with the view of determining how far structural dif ferences prevail over resemblances, and of ascertaining whether these differences possess that constant and untransitive character, which the naturalist requires as a justification of specific distinction. The physiologist searches
into the history of the vital functions in the several types of humanity, and seeks for in formation with regard to the permanence of anatomical differences, the effects of external agencies in modifying the configuration or constitution of the body, and the tendency to spontaneous variation in the forms presented by individuals, families, or tribes, known to be of the same stock. The psychologist has a most interesting subject of investigation, in the study of the psychical constitution of the several races, and in the extraction (so to speak) of their respective mental and moral characters, from their habits of life, their languages, and their religious observances. It is his business to inquire how far one com mon psychical character can be inferred from such diverse manifestations ; that is, how far the differences which he cannot but observe in intellectual capacity, and in moral and even instinctive tendencies, are fixed and per manent, or are liable to spontaneous variation, or to alteration from the modifying influence of education and other external conditions. The physical geographer lends his aid, by bringing to bear upon the inquiry his know ledge of the outward circumstances under which these variations in bodily and mental constitution are most constantly found. And it is from the materials which he contributes, that the physiologist and the anatomist have to determine the degree in which these cir cumstances can be justly considered as the causes of variation ; and, more especially, whether the coincidences between particular bodily configurations or mental constitutions, and certain combinations of climatic and geo logical conditions, are the result of induced differences among the human races which are respectively subject to the latter, or are to be attributed to the implantation of originally dissimilar stocks in the respective localities in which their descendants are now found. But in order to carry on these researches, the information of the historian is continually needed, on the actual descent, migrations, conquests, &c. of the nations whose physical and mental characters we are comparing. The question of the fixity of all or any of the characters by which the races of mankind are at present distinguished from each other, requires for its solution a comparison of the present with the past. No valid proof of their permanence can be drawn from the limited experience of a few generations; and no evidence of change can be reasonably looked for, except under the long-continued agency of modifying causes. The required information is sometimes supplied by direct historical testimony ; but this is frequently insufficient, and recourse must be then had to the philologist, who derives from the compara tive study of the languages of different tribes, most important evidence as to their degree of filiation, and thus extends, combines, and con firms the indications, which the historian had drawn from other sources. Independent of the aid which philological research affords to other departments of ethnology, it directly bears upon the great problem of the unity or identity of mankind ; for it not only answers a common purpose with historical testimony, in establishing the genealogical relations of tribes long since dispersed from their original centres, and separated at present by strongly marked physical and psychical differences ; but it also affords important evidence as to the fundamental similarity, if not identity, of the primitive stocks.