The great antiquity of mankind upon the earth has been conclusively established. It seems singular that the proofs should have been discovered as recently as within the last thirty years, and that the present generation should be the first called upon to recognize so important a fact.

Mankind are now known to have existed in Europe in the glacial period, and even back of its commencement, with every probability of their origination in a prior geological age. They have survived many races of animals with whom they were contemporaneous, and passed through a process of development, in the several branches of the human family, as remarkable in its courses as in its progress.

Since the probable length of their career is connected with geological periods, a limited measure of time is excluded. One hundred or two hundred thousand years would be an unextravagant estimate of the period from the disappearance of the glaciers in the northern hemisphere to the present time. Whatever doubts may attend any estimate of a period, the actual duration of which is unknown, the existence of mankind extends backward immeasurably, and loses itself in a vast and profound antiquity.

This knowledge changes materially the views which have prevailed respecting the relations of savages to barbarians, and of barbarians to civilized men. It can now be asserted upon convincing evidence that savagery preceded barbarism in all the tribes of mankind, as barbarism is known to have preceded civilization. The history of the human race is one in source, one in experience, and one in progress.

It is both a natural and a proper desire to learn, if possible, how all these ages upon ages of past time have been expended by mankind; how savages, advancing by slow, almost imperceptible steps, attained the higher condition of barbarians; how barbarians, by similar progressive advancement, finally attained to civilization; and why other tribes and nations have been left behind in the race of progress—some in civilization, some in barbarism, and others in savagery. It is not too much to expect that ultimately these several questions will be answered.

Inventions and discoveries stand in serial relations along the lines of human progress, and register its successive stages; while social and civil institutions, in virtue of their connection with perpetual human wants, have been developed from a few primary germs of thought. They exhibit a similar register of progress. These institutions, inventions and discoveries have embodied and preserved the principal facts now remaining illustrative of this experience. When collated and compared they tend to show the unity of origin of mankind, the similarity of human wants in the same stage of advancement, and the uniformity of the operations of the human mind in similar conditions of society.

Throughout the latter part of the period of savagery, and the entire period of barbarism, mankind in general were organized in gentes, phratries and tribes. These organizations prevailed throughout the entire ancient world upon all the continents, and were the instrumentalities by means of which ancient society was organized and held together. Their structure, and relations as members of an organic series, and the rights, privileges and obligations of the members of the gens, and of the members of the phratry and tribe, illustrate the growth of the idea of government in the human mind. The principal institutions of mankind originated in savagery, were developed in barbarism, and are maturing in civilization.

In like manner, the family has passed through successive forms, and created great systems of consanguinity and affinity which have remained to the present time. These systems, which record the relationships existing in the family of the period, when each system respectively was formed, contain an instructive record of the experience of mankind while the family was advancing from the consanguine, through intermediate forms, to the monogamian.

The idea of property has undergone a similar growth and development. Commencing at zero in savagery, the passion for the possession of property, as the representative of accumulated subsistence, has now become dominant over the human mind in civilized races.

The four classes of facts above indicated, and which extend themselves in parallel lines along the pathways of human progress from savagery to civilization, form the principal subjects of discussion in this volume.

There is one field of labor in which, as Americans, we have a special interest as well as a special duty. Rich as the American continent is known to be in material wealth, it is also the richest of all the continents in ethnological, philological and archÆological materials, illustrative of the great period of barbarism. Since mankind were one in origin, their career has been essentially one, running in different but uniform channels upon all continents, and very similarly in all the tribes and nations of mankind down to the same status of advancement. It follows that the history and experience of the American Indian tribes represent, more or less nearly, the history and experience of our own remote ancestors when in corresponding conditions. Forming a part of the human record, their institutions, arts, inventions and practical experience possess a high and special value reaching far beyond the Indian race itself.

When discovered, the American Indian tribes represented three distinct ethnical periods, and more completely than they were elsewhere then represented upon the earth. Materials for ethnology, philology and archÆology were offered in unparalleled abundance; but as these sciences scarcely existed until the present century, and are but feebly prosecuted among us at the present time, the workmen have been unequal to the work. Moreover, while fossil remains buried in the earth will keep for the future student, the remains of Indian arts, languages and institutions will not. They are perishing daily, and have been perishing for upwards of three centuries. The ethnic life of the Indian tribes is declining under the influence of American civilization, their arts and languages are disappearing, and their institutions are dissolving. After a few more years, facts that may now be gathered with ease will become impossible of discovery. These circumstances appeal strongly to Americans to enter this great field and gather its abundant harvest.

Rochester, New York, March, 1877.