Assuming the desirability of distributive justice, we may ask ourselves the nature of its aim. The essential element in the definition of justice itself seems to be the idea of an inflexible rule, applicable to all individuals without distinction. Such a rule is given in the Kantian formula of the categorical imperative; but here a content is lacking. Its determination involves the adoption of an end, which can only be derived from considerations of social utility. That is, the end adopted must be economic—economy being defined as the art of carrying to a maximum that well being which procures for man the enjoyment of exchangeable goods. Economic ends are the most universal of all: they are those which mankind in general ranks as most important. And rightly so, for until the needs of the organism—food, clothing, and shelter—are satisfied, no other progress is possible. Therefore, it may be said that the end sought by distributive justice is, as the usual conceptions of it denote, an economic end.
There are three fundamental philosophical methods. These correspond to three fundamental endowments of the human mind, and to three fundamental realities with which our experience has to deal. The scientific method, in its interpretation of the world, confines itself to the observation, classification, and generalization of the facts of sense perception. In its extreme form, this method issues in materialism; its less pronounced phases are empiricism, positivism, phenomenalism. A second method, characteristic of the pre-Socratic systems and the beginnings of modern philosophy, is a priori and rationalistic. A third method appears in the Socratic turning to the study of man, and in the Kantian appeal from the sceptical empiricism of Hume to the intuitions of the moral reason. This historical cycle of methods signifies that "there are three spheres of truth, three methods of inquiry, three standpoints and postulates, three sets of criteria, and that each of these has its rights, and that, if any one of them is denied its due place, error is the result." The rationalist, overestimating the forms of thinking at the expense of the content of thought, neglects the facts of experience. The empiricist errs in the opposite direction, fixing his attention upon particulars, and failing to provide for generalized knowledge. The third method, giving exaggerated prominence to the moral element in experience, results in excessive subjectivity. In a true philosophy these three factors must be reconciled. The facts of nature and of history, the interpretation of facts through reasoning, the insight and authority of the ethical nature, these are elements of truth, to all of which due recognition must be given. Both in philosophy and theology, the rationalistic type has predominated over the other two. Descartes' s method
