An Introduction to Philosophy - George Stuart Fullerton (i can read book club TXT) 📗

Why should not a man test his ideas by turning to things and comparing the former with the latter? On the other hand, he knows that to perceive things we must have sense organs and sensations, and he cannot quarrel with the psychologists for saying that we know things only in so far as they are revealed to us through our sensations. How does he reconcile these two positions? He does not reconcile them. He accepts them as they stand.

Reid and various other philosophers have tried to come back to "Common Sense" and to stay there. Now, it is a good position to come back to for the purpose of starting out again. The experience of the plain man, the truths which he recognizes as truths, these are not things to be despised. Many a man whose mind has been, as Berkeley expresses it, "debauched by learning," has gotten away from them to his detriment, and has said very unreasonable things. But "Common Sense" cannot be the ultimate refuge of the philosopher; it can only serve him as material for investigation. The scholar whose thought is as vague and inconsistent as that of the plain man has little profit in the fact that the apparatus of his learning has made it possible for him to be ponderously and unintelligibly vague and inconsistent.

Hence, we may have the utmost sympathy with Reid's protest against the doctrine of representative perception, and we may, nevertheless, complain that he has done little to explain how it is that we directly know external things and yet cannot be said to know things except in so far as we have sensations or ideas.

51. THE CRITICAL PHILOSOPHY.—The German philosopher, Immanuel Kant (1724-1804), was moved, by the skeptical conclusions to which Hume's philosophy seemed to lead, to seek a way of escape, somewhat as Reid was. But he did not take refuge in "Common Sense"; he developed an ingenious doctrine which has had an enormous influence in the philosophical world, and has given rise to a Kantian literature of such proportions that no man can hope to read all of it, even if he devotes his life to it. In Germany and out of it, it has for a hundred years and more simply rained books, pamphlets, and articles on Kant and his philosophy, some of them good, many of them far from clear and far from original. Hundreds of German university students have taken Kant as the subject of the dissertation by which they hoped to win the degree of Doctor of Philosophy;—I was lately offered two hundred and seventy-four such dissertations in one bunch;—and no student is supposed to have even a moderate knowledge of philosophy who has not an acquaintance with that famous work, the "Critique of Pure Reason."

It is to be expected from the outset that, where so many have found so much to say, there should reign abundant differences of opinion. There are differences of opinion touching the interpretation of Kant, and touching the criticisms which may be made upon, and the development which should be given to, his doctrine. It is, of course, impossible to go into all these things here; and I shall do no more than indicate, in untechnical language and in briefest outline, what he offers us in place of the philosophy of Hume.

Kant did not try to refute, as did Reid, the doctrine, urged by Descartes and by his successors, that all those things which the mind directly perceives are to be regarded as complexes of ideas. On the contrary, he accepted it, and he has made the words "phenomenon" and "noumenon" household words in philosophy.

The world which seems to be spread out before us in space and time is, he tells us, a world of things as they are revealed to our senses and our intelligence; it is a world of manifestations, of phenomena. What things-in-themselves are like we have no means of knowing; we know only things as they appear to us. We may, to be sure, talk of a something distinct from phenomena, a something not revealed to the senses, but thought of, a noumenon; but we should not forget that this is a negative conception; there is nothing in our experience that can give it a filling, for our experience is only of phenomena. The reader will find an unmistakable echo of this doctrine in Herbert Spencer's doctrine of the "Unknowable" and its "manifestations."

Now, Berkeley had called all the things we immediately perceive ideas. As we have seen, he distinguished between "ideas of sense" and "ideas of memory and imagination." Hume preferred to give to these two classes different names—he called the first impressions and the second ideas.

The associations of the word "impression" are not to be mistaken. Locke had taught that between ideas in the memory and genuine sensations there is the difference that the latter are due to the "brisk acting" of objects without us. Objects impress us, and we have sensations or impressions. To be sure, Hume, after employing the word "impression," goes on to argue that we have no evidence that there are external objects, which cause impressions. But he retains the word "impression," nevertheless, and his use of it perceptibly colors his thought.

In Kant's distinction between phenomena and noumena we have the lineal descendant of the old distinction between the circle of our ideas and the something outside of them that causes them and of which they are supposed to give information. Hume said we have no reason to believe such a thing exists, but are impelled by our nature to believe in it. Kant is not so much concerned to prove the nonexistence of noumena, things-in-themselves, as he is to prove that the very conception is an empty one. His reasonings seem to result in the conclusion that we can make no intelligible statement about things so cut off from our experience as noumena are supposed to be; and one would imagine that he would have felt impelled to go on to the frank declaration that we have no reason to believe in noumena at all, and had better throw away altogether so meaningless and useless a notion. But he was a conservative creature, and he did not go quite so far.

So far there is little choice between Kant and Hume. Certainly the former does not appear to have rehabilitated the external world which had suffered from the assaults of his predecessors. What important difference is there between his doctrine and that of the man whose skeptical tendencies he wished to combat?

The difference is this: Descartes and Locke had accounted for our knowledge of things by maintaining that things act upon us, and make an impression or sensation—that their action, so to speak, begets ideas. This is a very ancient doctrine as well as a very modern one; it is the doctrine that most men find reasonable even before they devote themselves to the study of philosophy. The totality of such impressions received from the external world, they are accustomed to regard as our experience of external things; and they are inclined to think that any knowledge of external things not founded upon experience can hardly deserve the name of knowledge.

Now, Hume, when he cast doubt upon the existence of external things, did not, as I have said above, divest himself of the suggestions of the word "impression." He insists strenuously that all our knowledge is founded upon experience; and he holds that no experience can give us knowledge that is necessary and universal. We know things as they are revealed to us in our experience; but who can guarantee that we may not have new experiences of a quite different kind, and which flatly contradict the notions which we have so far attained of what is possible and impossible, true and untrue.

It is here that Kant takes issue with Hume. A survey of our knowledge makes clear, he thinks, that we are in the possession of a great deal of information that is not of the unsatisfactory kind that, according to Hume, all our knowledge of things must be. There, for example, are all the truths of mathematics. When we enunciate a truth regarding the relations of the lines and angles of a triangle, we are not merely unfolding in the predicate of our proposition what was implicitly contained in the subject. There are propositions that do no more than this; they are analytical, i.e. they merely analyze the subject. Thus, when we say: Man is a rational animal, we may merely be defining the word "man"—unpacking it, so to speak. But a synthetic judgment is one in which the predicate is not contained in the subject; it adds to one's information. The mathematical truths are of this character. So also is the truth that everything that happens must have a cause.

Do we connect things with one another in this way merely because we have had experience that they are thus connected? Is it because they are given to us connected in this way? That cannot be the case, Kant argues, for what is taken up as mere experienced act cannot be known as universally and necessarily true. We perceive that these things must be so connected. How shall we explain this necessity?

We can only explain it, said Kant, in this way: We must assume that what is given us from without is merely the raw material of sensation, the matter of our experience; and that the ordering of this matter, the arranging it into a world of phenomena, the furnishing of form, is the work of the mind. Thus, we must think of space, time, causality, and of all other relations which obtain between the elements of our experience, as due to the nature of the mind. It perceives the world of phenomena that it does, because it constructs that world. Its knowledge of things is stable and dependable because it cannot know any phenomenon which does not conform to its laws. The water poured into a cup must take the shape of the cup; and the raw materials poured into a mind must take the form of an orderly world, spread out in space and time.

Kant thought that with this turn he had placed human knowledge upon a satisfactory basis, and had, at the same time, indicated the limitations of human knowledge. If the world we perceive is a world which we make; if the forms of thought furnished by the mind have no other function than the ordering of the materials furnished by sense; then what can we say of that which may be beyond phenomena? What of noumena?

It seems clear that, on Kant's principles, we ought not to be able to say anything whatever of noumena. To say that such may exist appears absurd. All conceivable connection between them and existing things as we know them is cut off. We cannot think of a noumenon as a substance, for the notions of substance and quality have been declared to be only a scheme for the ordering of phenomena. Nor can we think of one as a cause of the sensations that we unite into a world, for just the same reason. We are shut up logically to the world of phenomena, and that world of phenomena is, after all, the successor of the world of ideas advocated by Berkeley.

This is not the place to discuss at length the value of Kant's contribution to philosophy.[3] There is something terrifying in the prodigious length at which it seems possible for men to discuss it. Kant called his doctrine "Criticism," because it undertook to establish the nature and limits of our knowledge. By some he has been hailed as a great enlightener, and by others he has been accused of being as dogmatic in his assumptions as those whom he disapproved.

But one thing he certainly has accomplished. He has made the words "phenomena" and "noumena" familiar to us all, and he has induced a vast number of men to accept it as established fact that it is not worth while to try to extend our knowledge beyond phenomena. One sees his influence in the writings of men who differ most widely from one another.

[1] "Essay," Book IV, Chapter XI, section 7.

[2] "An Inquiry into the Human Mind," Chapter V, section 5.

[3] The reader will find a criticism of the Critical Philosophy in Chapter XV.

CHAPTER XIII REALISM AND IDEALISM

52. REALISM.—The plain man is a