Let the reconciliation of whatever is true in my views with whatever is true in other systems come about in the fulness of calm and careful inquiry. - Robert Chambers

Phenomena appear, in a word, to be explicable on the ground of development. We have already seen that various leading animal forms represent stages in the embryotic progress of the highest—the human being. Our brain goes through the various stages of a fish's, a reptile's, and a mammifer's brain, and finally becomes human.

Meteoric stones have proved to be a verity, and not an impossibility. About the same time, the fact of so many Gloucestershire peasantry having attested the prevention of small-pox by a virus from the teats of a cow, would have been deemed a sufficient answer to the same pleading, by nine out of every ten of the best educated physicians in England. Jenner's statue in Trafalgar Square tells us how fallacious the objection would have been. It is to be observed regarding such objections, that they are almost invariably gratuitous and unproved. Were they always put to the test of experiment, how many might prove like meteorites and vaccination?

My sincere desire in the composition of the book was to give the true view of the history of nature, with as little disturbance as possible to existing beliefs, whether philosophical or religious.