I have to thank the editors of the _American Catholic Quarterly Review_, of the _Ave Maria_, and of _The Ecclesiastical Review_ and _The Dolphin_, for their kind permission to republish the articles which appeared originally in their pages. All of them, though substantially remaining the same, have been revised, modified in a number of particulars, and added to very considerably in most cases. The call for a second edition--the third thousand--of this little book is gratifying. Its sale encouraged the preparation of a Second Series of CATHOLIC CHURCHMEN IN SCIENCE, and now the continued demand suggests a Third Series, which will be issued during the year. Some minor corrections have been made in this edition, but the book is substantially the same. {ix} CONTENTS. PAGE PREFACE ix I. THE SUPPOSED OPPOSITION OF SCIENCE AND RELIGION 3 II. COPERNICUS AND HIS TIMES 15 III. BASIL VALENTINE. FOUNDER OF MODERN CHEMISTRY 45 IV. LINACRE: SCHOLAR, PHYSICIAN, PRIEST 79 V. FATHER KIRCHER, S.J. SCIENTIST, ORIENTALIST, AND COLLECTOR 111 VI. BISHOP STENSEN: ANATOMIST AND FATHER OF GEOLOGY 137 VII. ABBÉ HAÜY: FATHER OF CRYSTALLOGRAPHY 169 VIII. ABBOT MENDEL: A NEW OUTLOOK IN HEREDITY 195 {x} {1} I. THE SUPPOSED OPPOSITION OF SCIENCE AND RELIGION. {2} {3} I. THE SUPPOSED OPPOSITION OF SCIENCE AND RELIGION. A common impression prevails that there is serious, if not invincible, opposition between science and religion. This persuasion has been minimized to a great degree in recent years, and yet sufficient of it remains to make a great many people think that, if there is not entire incompatibility between science and religion, there is at least such a diversity of purposes and aims in these two great realms of human thought that those who cultivate one field are not able to appreciate the labors of those who occupy themselves in the other. Indeed, it is usually accepted as a truth that to follow science with assiduity is practically sure to lead to unorthodoxy in religion. This is supposed to be especially true if the acquisition of scientific knowledge is pursued along lines that involve original research and new investigation. Somehow, it is thought that any one who has a mind free enough from the influence of prejudice and tradition to become an original thinker or investigator, is inevitably prone to abandon the old orthodox lines of thought in respect to religion.