"Knowledge of the lowest kind," says Herbert Spencer, "is _un-unified_ knowledge; Science is _partially-unified_ knowledge; Philosophy is _completely-unified_ knowledge." [1] Science, he argues, means merely the family of the Sciences--stands for nothing more than the sum of knowledge formed of their contributions. Philosophy is the fusion of these contributions into a whole; it is knowledge of the greatest generality. In harmony with this notion Spencer produced a system of philosophy which includes the following: A volume entitled "First Principles," which undertakes to show what man can and what man cannot know; a treatise on the principles of biology; another on the principles of psychology; still another on the principles of sociology; and finally one on the principles of morality. To complete the scheme it would have been necessary to give an account of inorganic nature before going on to the phenomena of life, but our philosopher found the task too great and left this out. Now, Spencer was a man of genius, and one finds in his works many illuminating thoughts. But it is worthy of remark that those who praise his work in this or in that field are almost always men who have themselves worked in some other field and have an imperfect acquaintance with the particular field that they happen to be praising. The metaphysician finds the reasonings of the "First Principles" rather loose and inconclusive; the biologist pays little heed to the "Principles of Biology"; the sociologist finds Spencer not particularly accurate or careful in the field of his predilection. He has tried to be a professor of all the sciences, and it is too late in the world's history for him or for any man to cope with such a task. In the days of Plato a man might have hoped to accomplish it. 6. WHAT PHILOSOPHY MEANS IN OUR TIME.--It savors of temerity to write down such a title as that which heads the present section. There are men living to-day to whom philosophy means little else than the doctrine of Kant, or of Hegel, or of the brothers Caird, or of Herbert Spencer, or even of St. Thomas Aquinas, for we must not forget that many of the seminaries of learning in Europe and some in America still hold to the mediaeval church philosophy.