Most of the following lectures were written as much as eight or ten years ago, though additions and alterations have been made, from time to time, to adapt them to the progress of science. They were undertaken at the suggestion of my friend, Rev. Henry Neill, then of Hatfield, now of Lenox. I had no definite intention as to the use to be made of the lectures; but having for many years turned my attention to the bearings of science, and especially of geology, upon religion, I felt a desire to put upon paper the final results of my examinations. I threw them into the lecture form, that I might, if best, deliver them to the geological classes which I should instruct in the college with which I am connected. This I have done for many years, and also have used them in various places before lyceums. They are at length published, from a conviction that something of the kind, from some quarter, is needed. Many of the thoughts, indeed, which, at the time they were put upon paper, were original, have since been brought out by other writers. Yet enough of this description probably remain to expose me to severe criticism. I beg the intelligent Christian, however, before he condemns my views, to settle it in his mind what he can substitute for them that will be more honorable to religion. It is much easier to find fault with a mode of defending the truth than to invent a better method. We may not be pleased with certain views in vindication of religion, and yet the alternative of rejecting them may be so much worse as to lead us at least to be silent. Would that Christian critics had always kept this fact in mind when writing upon the views of geologists! They would find often that they are straining at a gnat and must swallow a camel. If my views are erroneous, as exhibited in these lectures, I cannot plead that they have been hastily adopted. Most of them, indeed, have been the subjects of thought occasionally for thirty years. I hope, however, that all my suggestions will not be thought of equal importance in my own estimation; since some of them are merely hypothetical hints thrown out for the consideration of abler minds. This work does not exhibit quite so much of logical exactness as I could wish. But my leading object has been fully carried out, viz., to exhibit all the religious bearings of geology. Several of the lectures, however, have been written as if independent of all the rest; and, therefore, the reader will find some leading thoughts repeated, but always in different connections.