The Approach to Philosophy

by Ralph Barton Perry

§ [185]. When at the close of the sixteenth century the Frenchman, René Descartes, sought to construct philosophy anew and upon secure foundations, he too selected as the initial certainty of thought the thinker's knowledge of himself. This principle now received its classic formulation in the proposition, Cogito ergo sum—"I think, hence I am." The argument does not differ essentially from that of St. Augustine, but it now finds a place in a systematic and critical metaphysics. In that my thinking is certain of itself, says Descartes, in that I know myself before I know aught else, my self can never be dependent for its being upon anything else that I may come to know. A thinking self, with its knowledge and its volition, is quite capable of subsisting of itself. Such is, indeed, not the case with a finite self, for all finitude is significant of limitation, and in recognizing my limitations I postulate the infinite being or God. But the relation of my self to a physical world is quite without necessity. Human nature, with soul and body conjoined, is a combination of two substances, neither of which is a necessary consequence of the other. As a result of this combination the soul is to some extent affected by the body, and the body is to some extent directed by the soul; but the body could conceivably be an automaton, as the soul could conceivably be, and will in another life become, a free spirit. The consequences of this dualism for epistemology are very grave. If knowledge be the activity of a self-subsistent thinking spirit, how can it reveal the nature of an external world? The natural order is now literally "external." It is true that the whole body of exact science, that mechanical system to which Descartes attached so much importance, falls within the range of the soul's own thinking. But what assurance is there that it refers to a province of its own—a physical world in space? Descartes can only suppose that "clear and distinct" ideas must be trusted as faithful representations. It is true the external world makes its presence known directly, when it breaks in upon the soul in sense-perception. But Descartes's rationalism and love of mathematics forbade his attaching importance to this criterion. Real nature, that exactly definable and predictable order of moving bodies defined in physics, is not known through sense-perception, but through thought. Its necessities are the necessities of reason. Descartes finds himself, then, in the perplexing position of seeking an internal criterion for an external world. The problem of knowledge so stated sets going the whole epistemological movement of the eighteenth century, from Locke through Berkeley and Hume to Kant. And the issue of this development is the absolute idealism of Kant's successors.

Empirical Reaction of the English Philosophers.

§ [186]. Of the English philosophers who prepare the way for the epistemology of Kant, Hume is the most radical and momentous. It was he who roused Kant from his "dogmatic slumbers" to the task of the "Critical Philosophy." Hume is one of the two possible consequences of Descartes. One who attaches greater importance to the rational necessities of science than to its external reference, is not unwilling that nature should be swallowed up in mind. With Malebranche, Descartes's immediate successor in France, nature is thus provided for within the archetypal mind of God. With the English philosophers, on the other hand, externality is made the very mark of nature, and as a consequence sense-perception becomes the criterion of scientific truth. This empirical theory of knowledge, inaugurated and developed by Locke and Berkeley, culminates in Hume's designation of the impression as the distinguishing element of nature, at once making up its content and certifying to its externality. The processes of nature are successions of impressions; and the laws of nature are their uniformities, or the expectations of uniformity which their repetitions engender. Hume does not hesitate to draw the logical conclusion. If the final mark of truth is the presence to sense of the individual element, then science can consist only of items of information and probable generalizations concerning their sequences. The effect is observed to follow upon the cause in fact, but there is no understanding of its necessity; therefore no absolute certainty attaches to the future effects of any cause.

To Save Exact Science Kant Makes it Dependent on Mind.

§ [187]. But what has become of the dream of the mathematical physicist? Is the whole system of Newton, that brilliant triumph of the mechanical method, unfounded and dogmatic? It is the logical instability of this body of knowledge, made manifest in the well-founded scepticism of Hume, that rouses Kant to a reëxamination of the whole foundation of natural science. The general outline of his analysis has been developed above. It is of importance here to understand its relations to the problem of Descartes. Contrary to the view of the English philosophers, natural science is, says Kant, the work of the mind. The certainty of the causal relation is due to the human inability to think otherwise. Hume is mistaken in supposing that mere sensation gives us any knowledge of nature. The very least experience of objects involves the employment of principles which are furnished by the mind. Without the employment of such principles, or in bare sensation, there is no intelligible meaning whatsoever. But once admit the employment of such principles and formulate them systematically, and the whole Newtonian order of nature is seen to follow from them. Furthermore, since these principles or categories are the conditions of human experience, are the very instruments of knowledge, they are valid wherever there is any experience or knowledge. There is but one way to make anything at all out of nature, and that is to conceive it as an order of necessary events in space and time. Newtonian science is part of such a general conception, and is therefore necessary if knowledge is to be possible at all, even the least. Thus Kant turns upon Hume, and shuts him up to the choice between the utter abnegation of all knowledge, including the knowledge of his own scepticism, and the acceptance of the whole body of exact science.

But with nature thus conditioned by the necessities of thought, what has become of its externality? That, Kant admits, has indeed vanished. Kant does not attempt, as did Descartes, to hold that the nature which mind constructs and controls, exists also outside of mind. The nature that is known is on that very account phenomenal, anthropocentric—created by its cognitive conditions. Descartes was right in maintaining that sense-perception certifies to the existence of a world outside the mind, but mistaken in calling it nature and identifying it with the realm of science. In short, Kant acknowledges the external world, and names it the thing-in-itself; but insists that because it is outside of mind it is outside of knowledge. Thus is the certainty of science saved at the cost of its metaphysical validity. It is necessarily true, but only of a conditioned or dependent world. And in saving science Kant has at the same time prejudiced metaphysics in general. For the human or naturalistic way of knowing is left in sole possession of the field, with the higher interest of reasons in the ultimate nature of being, degraded to the rank of practical faith.

The Post-Kantians Transform Kant's Mind-in-general into an Absolute Mind.

§ [188]. The transformation of this critical and agnostic doctrine into absolute idealism is inevitable. The metaphysical interest was bound to avail itself of the speculative suggestiveness with which the Kantian philosophy abounds. The transformation turns upon Kant's assumption that whatever is constructed by the mind is on that account phenomenon or appearance. Kant has carried along the presumption that whatever is act or content of mind is on that account not real object or thing-in-itself. We have seen that this is generally accepted as true of the relativities of sense-perception. But is it true of thought? The post-Kantian idealist maintains that that depends upon the thought. The content of private individual thinking is in so far not real object; but it does not follow that this is true of such thinking as is universally valid. Now Kant has deduced his categories for thought in general. There are no empirical cases of thinking except the human thinkers; but the categories are not the property of any one human individual or any group of such individuals. They are the conditions of experience in general, and of every possibility of experience. The transition to absolute idealism is now readily made. Thought in general becomes the absolute mind, and experience in general its content. The thing-in-itself drops out as having no meaning. The objectivity to which it testified is provided for in the completeness and self-sufficiency which is attributed to the absolute experience. Indeed, an altogether new definition of subjective and objective replaces the old. The subjective is that which is only insufficiently thought, as in the case of relativity and error; the objective is that which is completely thought. Thus the natural order is indeed phenomenal; but only because the principles of science are not the highest principles of thought, and not because nature is the fruit of thought. Thus Hegel expresses his relation to Kant as follows:

"According to Kant, the things that we know about are to us appearances only, and we can never know their essential nature, which belongs to another world, which we cannot approach. . . . The true statement of the case is as follows. The things of which we have direct consciousness are mere phenomena, not for us only, but in their own nature; and the true and proper case of these things, finite as they are, is to have their existence founded not in themselves, but in the universal divine idea. This view of things, it is true, is as idealist as Kant's, but in contradistinction to the subjective idealism of the Critical Philosophy should be termed Absolute Idealism."[382:9]

The Direct Argument. The Inference from the Finite Mind to the Infinite Mind.