The opening of Preface
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.