sufficient to satisfy an inquisitive and discriminating mind. That criterion of identity of species first suggested by the English naturalist, Ray, and afterwards more largely insisted on by Buffon, has been, since his age, most generally received; that is, the power of procreating an offspring, that shall be itself endued with similar prolific powers. The horse and the ass can produce a mule; but the mule being barren, shews that the sire and dam are of different species. It is acknowledged, however, that experiments on the procreative virtue of animals, never have been, and probably never will be made, in sufficient number, or with sufficient accuracy, to establish the criterion of Ray and Buffon as a certain and universal fact. If it were entitled to the rank of an incontrovertible principle in natural science, there could no longer be any doubt concerning the unity of the human species under all the various forms and appearances in which it has existed in the different regions of the globe.

Dr. Blumenbach observes that "animals ought to be ranked in the same species when their general form and properties resemble one another, and the differences which subsist among them may be derived from some degenerating cause." According to

this principle, if it be admitted, those only are to be esteemed of different species whose distinctive properties are so essential to each respectively, and so inherent in them, that they cannot be changed, or their differences accounted for, by the known operation of any physical, or moral causes. If this, then, be received as the acknowledged criterion of diversity of species, I doubt not being able to demon-: strate, in the progress of this essay, that all the varieties of men may have sprung from the same original stock. To whichever criterion, therefore, we appeal, the same conclusion will result.*

*It is amusing to see the critical reviewers in England, in their remarks on the first edition of this essay, attach so much importance, as they do, to a frivolous and dubious disquisition respecting the proper criterion of a distinct species, which could lead to no other result, by their own confession, than this, that no accurate criterion has ever been discovered by philosophers. If that be so, surely a discussion of the question, merely as an exhibition of learning in Natural Science, could have been of little importance towards an elucidation of the subject. "So loose and inconclusive is his reasoning, say they, that he has never enquired what really constitutes a different species. In botany, it is preserving the general and essential characters in changes of situation, and losing, in time, the accidental differences which climate and culture have produced. In animals, where the distinction ought to have begun, it has been neglected, [viz. by Naturalists]. If the production of a fertile off.

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The hypothesis that the human kind is divided into various species, radically different from one another, is commonly connected in the systems of philosophers with another opinion, which, however gen. eral the assent be which it has obtained, is equally contrary to true philosophy, and to the sacred history; I mean the primitive and absolute savagism of all the

spring be the criterion of the sameness of the species, men are, undoubtedly, of the same species. But this distinction is found to be fallacious, particularly in domestic animals. And, if carefully examined, we shall find that, in zoology, the species are not, in reality, ascertained with accuracy. We must, then, at last, refer to the botanical distinction."-Now what elucidation could my subject have received from such learned remarks, which leave the question in the same uncertainty in which they found it? "In zoology, they say, no criterion has been ascertained with accuracy;"-therefore they will apply to animals that which botanists have fixed for plants. Be it so. It differs not much from that which Dr. Blumenbach proposes both for plants and animals. And, agreeably to this criterion, it is the whole object of the essay to deduce the varieties of men, or to account for them, from what the Doctor calls degenerating causes; or, to shew, according to the botanical standard of the Reviewers, that men in all climates, "preserve the general and essential characters of the race, and will lose, in time, the accidental differences which climate, and culture, or the habits of living, and various states of society, have produced in them.” With what success this has been done I cheerfully leave to the philosophic reader to determine.

tribes of men. A few observations on this opinion calculated to demonstrate its utter improbability, if not its obvious falsehood, will not, I presume, be deemed impertinent to the object of the following essay; which is to confirm the doctrine of the unity of the human race, by pointing out the causes of its variety. As this argument, however, rests on an entirely different kind of proof, and is only incidentally related to my principal design, I shall present it to the reader with the greatest brevity. And I trust it will not be found to be an argument so trite, or so unimportant, as to render it, on either account, unworthy his serious attention.

The original, and absolute savagism of mankind, then, is a principle which appears to me to be contradicted equally by sound reason, and by the most authentic documents which remain to us of ancient history.* All the earliest monuments of nations, as far as we can trace them, fix their origin about the middle regions of Asia, and present man to us in a

* The argument from history will be found handsomely illustrated by Mr. David Doig of Sterling in Scotland, in three letters addressed to Lord Kaims, and published in one small duodecimo volume.

state already civilized. From this centre we perceive the radiations of the race gradually shooting themselves towards every quarter of the globe. Savage life seems to have arisen only from idle, or restless spirits, who, shunning the fatigues of labor, or spurning the restraints and subordinations of civil society, sought, at once, liberty, and the pleasures of the chace, in wild, uncultivated regions remote from their original habitations. Here, forgetting the arts of civilized life, they, with their posterity, degenerated, in a course of time, into all the ignorance and rudeness of savagism, and furnished ample materials to the imagination of the poets for the pictures they have presented to us of the abject condition of the primitive men. But let us consult reason, as well as history, for the truth, or probability of their pictures.

Hardly is it possible that man, placed on the surface of the new world, in the midst of its forests and marshes, capable of reason, indeed, but without having formed principles to direct its exercise, should have been able to preserve his existence, unless he had received from his Creator, along with his being, some instructions concerning the use and employment of his faculties, for procuring his subsistence, and in

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