PHILOSOPHY (Lat. philosophic, from Gk. rr ciSIXococpia, love of knowledge. from cbtXciv, /ei,m, to love ± croOta, sophia, wisdom, from crocb6s, sophos, wise). A term originally used, e.g. by Socrates, to mean devotion to the pursuit of truth. In Plato it came to mean knowledge of eternal reality. Aristotle employed the term sometimes as equivalent to critical systematized knowledge. sometimes as meaning the science of ultimate reality. The Stoics considered philos ophy to he the endeav'or to obtain excellence (apes- , arete)• in knowledge and in morality; the Epicureans regarded the philosopher as the man who pursued happiness in the manner sug gested by reason. In the Middle Ages philosophy came to be ancillary to theology, and in large measure the reasoned defense of divinely revealed truth. In modern times various definitions have been given, such as "rational knowledge derived from concepts as such" (Kant), "the revision of concepts" (Herbart), "the science of principles" (Ceberweg), "the totality (Inbeyrifi) of all scientific knowledge" (Paulsen). and •'the reduc tion of the general knowledge obtained by the special sciences to a complete system" (Wundt) ; while some thinkers have despaired of the pos sibility of finding any definition that shall cover the whole field historically occupied by philosoph ical speculation. The conception of the task of philosophy necessarily changes with the course of time. At the beginning, before any special sci ences had arisen, it was natural that the unity of knowledge should be insisted on, and that the student should ambitiously take all knowledge for his province. But the scope of philosophy has gradually grown narrower as its original domain has been encroached upon by new sci ences. The failure of philosophers of the present to agree on the definition of their work is due to the fact that so much territory has been al ready occupied by these sciences as to leave the proper domain of philosophy in doubt. These sciences have one and all been experiential in their method. To those who believe in the ex
istence of a priori knowledge, a point of departure for delimiting philosophy from science is obtained in this distinction of the inductive from the deductive. But the belief in a priori knowledge is less current than it was a hundred years ago. and some other differentiation of phil osophy from science must be undertaken by the induetivist. Perhaps no better plan can be adopted than that based upon the specialistic character of present-day science. Each science pursues its own investigations in its own limited field, and will allow itself to be prejudiced as little as possible by what is done in other fields. But after all it is the same universe that fur nishes object-matter to all the separate sciences. and one would naturally expect that all the sep arate knowledges gained by specialists would articulate themselves into a coherent system of knowledge. The hope to accomplish this articu lation in detail would he idle; but every science has its concepts, which it uses to organize the facts in its own little field. Do all the concepts tally? Are they compatible with each other? Questions of this sort are reasonable, and an at tempt to answer them forms the so-called philos ophy of nature, which may be defined as the cor relation and criticism of scientific concepts. Among such concepts are those of matter, energy and its conservation, atom. life. evolution. differ ential, point, line, etc. The philosophy of nature is without doubt the most difficult branch of philosophy, as it demands for its prosecution con siderable familiarity with the leading sciences. But while it is not to be hoped that any very gen eral treatment of the subject can he satisfactory, still more detailed work in the way of corre lation and criticism of the conceptions employed in a few sciences can be reasonably expected. Such work has been done in English by Stallo in his roncepts and Theories of Modern. Physics (London, ISS'2.), and by James Ward in his ..\at uralism and Agnosticism (bunion, 189J).