The reader is now informed of what he may expect to find discussed in this volume. It remains for me to indicate the mode in which the discussion will be carried on. I propose to divest my own mind, and so far as I may to divest the mind of the reader, of all influence from revealed religion. I shall not refer to the Mosaic account of the creation excepting as I refer to other hypotheses. With its authority as an account given by the Deity himself through his chosen servant, I have here nothing to do. Nor shall I rely upon the revelation recorded in the New Testament. All the inquiries which I propose to make are those which lie in the domain of natural religion; and while I can not expect, in exploring this domain, to make discoveries or to find arguments which can claim the merit of originality, I may avoid traveling in a well beaten path, by pursuing the line of my own reflections, without considering whether they coincide with or differ from the reasonings of others. Although, at a former period of my life, I have studied the great writers whose speculations in the science of natural theology are the most famous and important pieces in its literature, it is more than forty years since I have looked into one of them; and I do not propose to turn to them now, in order to see whether they have or have not left any traces in my mind. It is quite possible that critics may array against me the authority of some great name or names; but even if I am to be charged with presumption in entering upon this field, it will not be found, so far as I am conscious, that I have borrowed an argument, imitated a method, or followed an example.