This historical study traces in detail the gradual change in point of view in nineteenth century geology textbooks from religious fundamentalism to secularism. Scientific progress is identified as a major factor in bringing about this change. In the early decades of the nineteenth century authors stressed that geology was in accord with Christian doctrine. Indicated are changes that occurred in geology texts and the secular character of the texts in the closing decades of the nineteenth century. Issues prominent in earlier books received no discussion. Other issues formerly treated from a theistic viewpoint were discussed with no religious bias at all. The final chapter analyzes secularization with reference to the long standing conflict between religion and science. (BC)