§ 64. It is clear, furthermore, that the doctrine of Anaxagoras not only names a distinct kind of cause, but also ascribes to it an independence and intrinsic importance that do not belong to motion. Whereas motion is a property of matter, intelligence is an originative power working out purposes of its own choosing. Hence we have here to do with a new ontology. If we construe ultimate being in terms of mind, we have a definite substitute for the physical theories outlined above. Such a theory is scarcely to be attributed to any Greek philosopher of the early period; it belongs to a more sophisticated stage in the development of thought, after the rise of the problem of epistemology. But Anaxagoras's sharp distinction between the material of the world on the one hand, and the author of its order and evolution on the other, is in itself worthy of notice. It contains the germ of a recurrent philosophical _dualism_, which differs from pluralism in that it finds two and only two fundamental divisions of being, the physical, material, or potential on the one hand, and the mental, formal, or ideal on the other. [Sidenote: The New Meaning of Monism and Pluralism.] § 65. Finally, the alternative possibilities which these cosmological considerations introduce, bear directly upon the general question of the interdependence of the parts of the world, a question which has already appeared as pertinent in ontology. Monism and pluralism now obtain a new meaning. Where the world process is informed with some singleness of plan, as teleology proposes, the parts are reciprocally necessary, and inseparable from the unity. Where, on the other hand, the processes are random and reciprocally fortuitous, as Leucippus proposes, the world as a whole is an aggregate rather than a unity. In this way uniformity in kind of being may prevail in a world the relations of whose parts are due to chance, while diversity in kind of being may prevail in a world knit together by some thorough-going plan of organization. Thus monism and pluralism are conceptions as proper to cosmology as to ontology. But enough has been said to demonstrate the interdependence of ontology and cosmology, of the theory of being and the theory of differentiation and process. Such problems can be only abstractly sundered, and the distinctive character of any metaphysical system will usually consist in some theory determining their relation. Philosophy returns to these metaphysical problems with its thought enriched and its method complicated, after becoming thoroughly alive to the problems of epistemology, logic, and ethics. [Sidenote: Epistemology Seeks to Understand the Possibility of Knowledge.]