After acknowledging that more than a quarter of a century has elapsed since this subject first engaged my attention, it may be useless for me to ask any indulgence from criticism. But really, I feel less prepared to write upon it than I did during the first five years in which I studied it. I have learnt that it is a most difficult subject. It requires, in order to master it, an acquaintance with three distinct branches of knowledge, not apt to go together. First, an acquaintance with geology in all its details, and with the general principles of zoology, botany, and comparative anatomy; secondly, a knowledge of sacred hermeneutics, or the principles of interpreting the Scriptures; thirdly, a clear conception of the principles of natural and revealed religion. As examples of efforts made by men who were deficient in a knowledge of some of these branches, I am compelled to quote a large proportion of the works which, within the last thirty or forty years, have been written on the religion of geology; especially on its connection with revealed religion. I am happy to except such writers as Dr. J. Pye Smith, Dr. Chalmers, Dr. Harris, Dr. Buckland, Professor Sedgwick, Professor Whewell, Dr. King, Dr. Anderson, and Hugh Miller; for they, to a greater or less extent, acquainted themselves with all the subjects named above, before they undertook to write. But a still larger number of authors, although men of talents, and familiar, it may be, with the Bible and theology, had no accurate knowledge of geology. The results have been, first, that, by resorting to denunciation and charges of infidelity, to answer arguments from geology which they did not understand, they have excited unreasonable prejudices and alarm among common Christians respecting that science and its cultivators; secondly, they have awakened disgust, and even contempt, among scientific men, especially those of sceptical tendencies, who have inferred that a cause which resorts to such defences must be very weak. They have felt very much as a good Greek scholar would, who should read a severe critique upon the style of Isocrates, or Demosthenes, and, before he had finished the review, should discover internal evidence that the writer had never learnt the Greek alphabet. On the other hand, prejudices and disgust equally strong have been produced in the mind of many a man well versed in theology and biblical exegesis by some productions of scientific men upon the religious bearings of geology, because they advanced principles which the merest tyro in divinity would know to be false and fatal to religion, and which they advocated only because they had never studied the Bible or theology.