792 PHILOSOPHY affections on that which in each case really exists " (R?p., 480). In Plato, however, this distinction is applied chiefly in an ethical and religious direction ; and, while it defines philosophy, so far correctly, as the endeavour to express what things are in their ultimate constitution, it is not yet accompanied by a sufficient differentiation of the sub sidiary inquiries by which this ultimate question may be approached. Logic, ethics, and physics, psychology, theory of knowledge, and metaphysics are all fused together by Plato in a semi-religious synthesis. It is not till we come to Aristotle the encyclopedist of the ancient world that we find a demarcation of the different philosophic dis ciplines corresponding, in the main, to that still current. The earliest philosophers, or "physiologers," had occupied themselves chiefly with what we may call cosmology ; the one question which covers everything for them is that of the underlying substance of the world around them, and they essay to answer this question, so to speak, by simple inspection. In Socrates and Plato, on the other hand, the start is made from a consideration of man s moral and intellectual activity ; but knowledge and action are con fused with one another, as in the Socratic doctrine that virtue is knowledge. To this correspond the Platonic con fusion of logic and ethics and the attempt to substitute a theory of concepts for a metaphysic of reality. Aristotle s methodic intellect led him to separate the different aspects of reality here confounded. He became the founder of logic, psychology, ethics, and aesthetics as separate sciences ; while he prefixed to all such (comparatively) i Decial in quiries the investigation of the ultimate nature of existence as such, or of those first principles which are common to, and presupposed in, every narrower field of knowledge. For this investigation Aristotle s most usual name is " first philosophy"; but there has since been appropriated to it, apparently by accident, the title " metaphysics." " Philo sophy," as a term of general application, was not, indeed, restricted by Aristotle or his successors to the disciplines just enumerated. Aristotle himself includes under the title, besides mathematics, all his physical inquiries. It was only in the Alexandrian period, as Zeller points out, that the special sciences attained to independent cultivation. Nevertheless, as the mass of knowledge accumulated, it naturally came about that the name " philosophy " ceased to be applied to inquiries concerned with the particulars as such. The details of physics, for example, were aban doned to the scientific specialist, and philosophy restricted itself in this department to the question of the relation of the physical universe to the ultimate ground or author of things. This inquiry, w r hich was long called "rational cosmology," may be said to form part of the general science of metaphysics, or at all events a pendant to it. By the gradual sifting out of the special sciences philosophy thus came to embrace primarily the inquiries grouped as " meta physics " or first philosophy." These would embrace, according to the scheme long current, ontology proper, or the science of being as such, with its branch sciences of (rational) psychology, cosmology, and (rational or natural) theology. Subsidiary to metaphysics, as the central in quiry, stand the sciences of logic and ethics, to which may be added sestheticsj constituting three normative sciences, sciences, that is, which do not, primarily, describe facts, but rather prescribe ends. It is evident, however, that if logic deals with conceptions which may be considered con stitutive of knowledge as such, and if ethics deals with the harmonious realization of the highest known form of exist ence, both sciences must have a great deal of weight in the settling of the general question of metaphysics. Modern modifications of the above scheme will be pre sently considered ; but it is sufficiently accurate as a start ing-point, and its acceptance by so many generations of thinkers is a guarantee for its provisional intelligibility. Accordingly, we may say that "philosophy" has been under stood, during the greater part of its history, to be a general term covering the various disciplines just enumerated. It has frequently tended, however, and still tends, to be used as specially convertible with the narrower term " meta physics." This is not unnatural, seeing that it is only so far as they bear on the one central question of the nature of existence that philosophy spreads its mantle over psychology, logic, or ethics. The organic conditions of perception and the associative laws to which the mind, as a part of nature, is subjected, are nothing to the philosopher ; and therefore the handing over of (empirical) psychology to special investigators, which is at present taking place, can be productive of none but good results. Similarly, logic, so far as it is an art of thought or a doctrine of fallacies, and ethics, so far as it is occupied with a natural history of impulses and moral sentiments, do neither of them belong, except by courtesy, to the philosophic pro vince. But, although this is so, it is perhaps hardly desirable to deprive ourselves of the use of two terms instead of one. It will not be easy to infuse into so abstract and bloodless a term as " metaphysics " the fuller life (and especially the inclusion of ethical considerations) suggested by the more concrete term "philosophy." We shall first of all, then, attempt to differentiate philo sophy from the special sciences, and afterwards proceed to take up one by one what have been called the philosophical sciences, with the view of showing how far the usual sub ject-matter of each is really philosophical in its bearing, and how far it belongs rather to the domain of science strictly so called. We shall also see in the course of this inquiry in what these various philosophical disciplines differ from one another, and how far they merge into another, or have, as a matter of fact, been confused at different periods in the history of philosophy. The order in which, for clear ness of exposition, it wall be most convenient to consider these disciplines will be psychology, epistemology or theory of knowledge, and metaphysics, then logic, aesthetics, and ethics. Finally, the connexion of the last-mentioned with politics (or, to speak more modernly, with jurisprudence and sociology) and with the philosophy of history will call for a few words on the relation of these sciences to general philosophy. Philosophy and Science. In distinguishing philosophy from the sciences, it may not be amiss at the outset to guard against the possible misunderstanding that philo sophy is concerned with a subject-matter different from, and in some obscure way transcending, the subject-matter of the sciences. Now that psychology, or the observa tional and experimental study of mind, may be said to have been definitively included among the positive sciences, there is not even the apparent ground which once existed for such an idea. Philosophy, even under its most discredited name of metaphysics, has no other subject-matter than the nature of the real world, as that world lies around us in everyday life, and lies open to observers on every side. But if this is so, it may be asked what function can remain for philosophy when every portion of the field is already lotted out and enclosed by specialists 1 Philosophy claims to be the science of the whole ; but, if we get the knowledge of the parts from the different sciences, what is there left for philosophy to tell us 1 To this it is sufficient to answer generally that the synthesis of the parts is something more than that detailed knowledge of the parts in separa tion which is gained by the man of science. It is with the ultimate synthesis that philosophy concerns itself ; it has to show that the subject-matter which we are all deal ing with in detail really is a whole, consisting of articulated members. Evidently, therefore, the relation existing be-
