“ At the present day realism is despised on the ground that its differentiation of body and soul, natural and supernatural, ignores the unity of being. Indeed, in order to oppose this unity of being to the realistic duality, both materialists and idealists describe themselves as monists, and call realists dualists by way of disparagement. But we cannot classify metaphysics by the antithesis of monism and dualism without making confusion worse confounded. ”

“ To this pressing question then—What is the world as we know it?—three kinds of definite answers are returned: those of materialism, idealism and realism, according to the emphasis laid by metaphysicians on body, on mind, or on both. Metaphysical materialism is the view that everything known is body or matter; but while according to ancient materialists soul is only another body, according to modern materialists mind without soul is only an attribute or function of body. ”

“ Aristotle emphasized being as being, without always sufficiently asking whether the things whose existence he asserted are really knowable. We, on the contrary, mainly through the influence of Descartes, rather ask what are the things we know, and therefore, some more and some less, come to connect ontology with epistemology, and in consequence come to treat metaphysics in relation to psychology and logic, from which epistemology is an offshoot. ”

“ Metaphysical idealism is the view that everything known is mind, or some mental state or other, which some idealists suppose to require a substantial soul, others not; while all agree that body has no different being apart from mind. ”

“ On the other hand, it is the virtue of idealism to emphasize the fact of consciousness, but its vice to exaggerate it, with the consequence of resorting to every kind of paradox to deny the obvious and get rid of bodies. ”

“ Side by side with psychology, the science of mind, and with logic, the science of reasoning, metaphysics is tending gradually to reassert its ancient Aristotelian position as the science of being in general. ”

“ But with the decline of dogmatic belief and the spread of religious doubt—as the special sciences also grow more general, and the natural sciences become more speculative about matter and force, evolution and teleology—men begin to wonder again about the nature and origin of things, just as it was the decay of polytheism in Greek religion and his own discoveries in natural science which impelled Aristotle to metaphysical questions. ”