5. THE MODERN PHILOSOPHY.—The submission of men's minds to the authority of Aristotle and of the church gradually gave way. A revival of learning set in. Men turned first of all to a more independent choice of authorities, and then rose to the conception of a philosophy independent of authority, of a science based upon an observation of nature, of a science at first hand. The special sciences came into being.
But the old tradition of philosophy as universal knowledge remained. If we pass over the men of the transition period and turn our attention to Francis Bacon (1561–1626) and Rene Descartes (1596–1650), the two who are commonly regarded as heading the list of the modern philosophers, we find both of them assigning to the philosopher an almost unlimited field.
Bacon holds that philosophy has for its objects God, man, and nature, and he regards it as within his province to treat of "philosophia prima" (a sort of metaphysics, though he does not call it by this name), of logic, of physics and astronomy, of anthropology, in which he includes psychology, of ethics, and of politics. In short, he attempts to map out the whole field of human knowledge, and to tell those who work in this corner of it or in that how they should set about their task.
As for Descartes, he writes of the trustworthiness of human knowledge, of the existence of God, of the existence of an external world, of the human soul and its nature, of mathematics, physics, cosmology, physiology, and, in short, of nearly everything discussed by the men of his day. No man can accuse this extraordinary Frenchman of a lack of appreciation of the special sciences which were growing up. No one in his time had a better right to be called a scientist in the modern sense of the term. But it was not enough for him to be a mere mathematician, or even a worker in the physical sciences generally. He must be all that has been mentioned above.
The conception of philosophy as of a something that embraces all departments of human knowledge has not wholly passed away even in our day. I shall not dwell upon Spinoza (1632–1677), who believed it possible to deduce a world a priori with mathematical precision; upon Christian Wolff (1679–1754), who defined philosophy as the knowledge of the causes of what is or comes into being; upon Fichte (1762–1814), who believed that the philosopher, by mere thinking, could lay down the laws of all possible future experience; upon Schelling (1775–1854), who, without knowing anything worth mentioning about natural science, had the courage to develop a system of natural philosophy, and to condemn such investigators as Boyle and Newton; upon Hegel (1770–1831), who undertakes to construct the whole system of reality out of concepts, and who, with his immediate predecessors, brought philosophy for a while into more or less disrepute with men of a scientific turn of mind. I shall come down quite to our own times, and consider a man whose conception of philosophy has had and still has a good deal of influence, especially with the general public—with those to whom philosophy is a thing to be taken up in moments of leisure, and cannot be the serious pursuit of a life.
"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.
But let me gather up in a few words the purport of what has been said above. Philosophy once meant the whole body of scientific knowledge. Afterward it came to mean the whole body of knowledge which could be attained by the mere light of human reason, unaided by revelation. The several special sciences sprang up, and a multitude of men have for a long time past devoted themselves to definite limited fields of investigation with little attention to what has been done in other fields. Nevertheless, there has persisted the notion of a discipline which somehow concerns itself with the whole system of things, rather than with any limited division of that broad field. It is a notion not peculiar to the disciples of Spencer. There are many to whom philosophy is a "Weltweisheit," a world-wisdom. Shall we say that this is the meaning of the word philosophy now? And if we do, how shall we draw a line between philosophy and the body of the special sciences?
Perhaps the most just way to get a preliminary idea of what philosophy means to the men of our time is to turn away for the time being from the definition of any one man or group of men, and to ask ourselves what a professor of philosophy in an American or European university is actually supposed to teach.
It is quite clear that he is not supposed to be an Aristotle. He does not represent all the sciences, and no one expects him to lecture on mathematics, mechanics, physics, chemistry, zoölogy, botany, economics, politics, and various other disciplines. There was a time when he might have been expected to teach all that men could know, but that time is long past.
Nevertheless, there is quite a group of sciences which are regarded as belonging especially to his province; and although a man may devote a large part of his attention to some one portion of the field, he would certainly be thought remiss if he wholly neglected the rest. This group of sciences includes logic, psychology, ethics and aesthetics, metaphysics, and the history of philosophy. I have not included epistemology or the "theory of knowledge" as a separate discipline, for reasons which will appear later (Chapter XIX); and I have included the history of philosophy, because, whether we care to call this a special science or not, it constitutes a very important part of the work of the teacher of philosophy in our day.
Of this group of subjects the student who goes to the university to study philosophy is supposed to know something before he leaves its walls, whatever else he may or may not know.
It should be remarked, again, that there is commonly supposed to be a peculiarly close relation between philosophy and religion. Certainly, if any one about a university undertakes to give a course of lectures on theism, it is much more apt to be the professor of philosophy than the professor of mathematics or of chemistry. The man who has written an "Introduction to Philosophy," a "Psychology," a "Logic," and an "Outlines of Metaphysics" is very apt to regard it as his duty to add to the list a "Philosophy of Religion." The students in the theological seminaries of Europe and America are usually encouraged, if not compelled, to attend courses in philosophy.
Finally, it appears to be definitely accepted that even the disciplines that we never think of classing among the philosophical sciences are not wholly cut off from a connection