The author of this work is one of the most eminent physicians in Belgium. He is Professor of General Pathology and Therapeutics in the Catholic University of Louvain; for nearly twenty years he has been at the head of the medical staff of two establishments for the cure of mental diseases, during which period he has also delivered courses of lectures upon the same subject; and he has as extensive a private practice as it is possible for any one man to attend to. Those who have the privilege of his private acquaintance speak in the highest terms both of his moral and intellectual qualities; his keenness of observation, sound sense, and perfect integrity. In a word, no quality seems to be wanting to him which the most fastidious of critics could desire in a witness on so delicate and important an investigation as that which is recorded in the following pages.<br><br>In the course of the work, Dr. Lefebvre makes many apologies for seeming to trespass on the domain of theology; and, by parity of reasoning, I too am bound to apologise for editing a treatise which is essentially medical.