KANT

The Convergence of Philosophical Influences in Germany. The intellectual thoroughfare from the past into our modern times does not pass in the eighteenth century through England, nor yet through France, but by way of Germany. Traditional France ended with the French political revolution, while the English empirical movement proved its own inconsistency in the phenomenalism of Hume. In Germany alone, at the close of the eighteenth century, there was a renewed and brilliant intellectual life. In its creative productions it has been compared by the Germans to the Systematic Period of Greek thought (from the death of Socrates to that of Aristotle). Both periods appeared when the political fortunes of the respective countries were at their lowest ebb.

There were six large influences that converged upon this epoch, some of which we have already noted as beginning even as far back as the period introductory to the Enlightenment (1648–1740) (see pp. 217 ff.). Some are later in their origin or come from a foreign source. Let us merely enumerate them here.

(1) Pietism, the religious influence that began with Spener (1635) and swept Germany in the eighteenth century; (2) The sentimentalism of Rousseau; (3) The empirical psychology of Locke among the younger Germans; (4) The Rationalism of the Leibnitz-Wolffian philosophy, which was most powerful in academic circles; (5) The mathematical rigorism of the nature-philosophy of Newton; (6) The new literary writers in their insistence upon subjectivity and intuition.

The Three Characteristics of German Philosophy. German philosophy will be seen to have three characteristics. (1) It is scholastic or academic. It is the philosophy of the professors of universities. At the same time it must be said to be the expression of the social genius of the German people. Napoleon testified to this when he said, “The English inhabit the sea, the French the land, the Germans the air.” (2) This German philosophy is mystical. It is profound rather than external. It is not founded upon external experience, but upon a questioning of the inner and spiritual life. It is inward, religious, and spiritual, like the philosophy of Plato. One of the most accurate interpreters of Kant has pointed out the many similarities between Kant and Plato (see Paulsen, Immanuel Kant). (3) German philosophy was nevertheless cosmic, or a description of the world. These men whom we are now to study were not ignorant of the world or of science. Political life offered them no attractions. The soul of man was regarded by them as too noble to be engrossed in external things. As Madame De Staël said of the time, “There was nothing to do save for him whose concern was with the universe.” Men, however, took the inner point of view, and regarded all things with reference to it. The Germans tried to humanize the universe. They looked upon nature as working out unconsciously those processes which consciously took place in man. The contemplation of beauty is not that of an external world, but of the inmost nature of reality. Thus individuality and cosmic reality are one and the same. Life has a joyful outlook, not because our tasks are easy, but because our strength is equal to them; for is not God in us?

The Two Periods of German Philosophy. German philosophy is divided into two epochs: (1) the period of the formation of the critical theory of knowledge by Kant; (2) the period of the metaphysical development of Fichte, Schelling, Hegel, Herbart, and Schopenhauer. Kant belongs both to the Enlightenment and to German idealism. He is the point of convergence of the intellectual forces that preceded him and the point of departure of the idealists who followed him. For this reason historians differ as to the period in which he is to be placed. In one sense he is the transition from the Enlightenment, in another sense he is the introduction of German idealism. But in reality he forms an epoch between the two. Although the dualism, which was always the background of the philosophy of the Enlightenment, formed too the background of his thought, although he on the other hand looked upon his Critique of Pure Reason as only an introduction to a metaphysics, which he never wrote, nevertheless he occupies a unique place in drawing up for his time and for the future a new conceptual standard by which the new problems might be criticised. The problem that Kant set before himself was epistemological and not one of metaphysics.

After Kant there appeared a growth of metaphysics. The great German idealistic systems appeared. At first the Kantian theory was misunderstood, but at Jena, then the chief intellectual centre in Germany, there was formed a little group of Kantians under the leadership of Rheinhold. Jena is near Weimar (see map p. 280), which was the main literary city of Germany, and the residence of Goethe. The poetry of Weimar and the philosophy of Jena stimulated each other. Schiller is a notable example of the influence of Kant upon the literature of the time. In philosophy Kant was followed by the various systems of Fichte, Schelling, Hegel, Herbart, and Schopenhauer, which built a metaphysical superstructure upon the Kantian foundation.

The Influences upon Kant. The development of Kant’s thought was modified by influences from at least five different sources.

1. Pietism. This was the earliest influence upon his life, and was due to his parents and to F. A. Schultze, the teacher of the high school of Königsberg. It will be remembered that this ethical Puritanism was a moral reaction against the formalism of the churches in the period after the Thirty Years’ War. Kant never lost his attachment for the Pietists; and his later rigoristic ethical theory, as well as his own personal life, sprang from his early Pietistic training. Schiller wrote to Goethe, “There is always something about Kant, as about Luther, which reminds one of the monk, who has indeed quitted his cloister, but who can never quite rid himself of its traces.”

2. The Leibnitz-Wolffian Philosophy. This influence came during his academic training in the University of Königsberg, which he entered upon at the age of sixteen years. This was in 1740, the same year in which Frederick was crowned and Wolff was recalled to Halle,—the time when the Leibnitz-Wolffian philosophy was at the fullness of control of Germany. It must not be forgotten that this philosophy remained dominant in German academic circles until Kant’s own theory supplanted it in the nineties. Kant was an avowed disciple of the Wolffian school for the next twenty years (until 1760), and he never shook off the Wolffian metaphysical dualism.

3. The Physics of Newton. To his university training Kant was indebted also for his acquaintance with Newton. The antagonism between the metaphysics of Wolff and the physics of Newton was, at least at the beginning of Kant’s career, of decisive importance in his development. One of Kant’s teachers at the university was Martin Knutzen, whose lectures included philosophy, mathematics, and natural science. Through personal intercourse with Knutzen, the young Kant was introduced to the Wolffian philosophy, and also to the Newtonian mathematics and physics. During his activity as a teacher Kant showed, even into his later period, a predilection for natural science, especially for physical geography and anthropology. The same year in which he entered upon his career as teacher in the University of Königsberg (1755), he published his celebrated Theory of the Heavens, in which he anticipated Laplace by forty years in the formulation of the nebular hypothesis.

4. The Humanitarianism of Rousseau. Kant got from Rousseau a new evaluation of man. Kant had the advantage of a prolonged youthful development. He was well into his thirties when the movement, begun by Lessing, became a social force in Germany. A new political consciousness appeared among the German people, due to the influence of Frederick the Great and to that of the Frenchmen, Voltaire and Rousseau. Kant was thirty-eight (in 1762) when he read Rousseau’s Emile. Kant had been brought up in the common teaching of the early part of the Enlightenment to despise the ignorant masses of people. Through Rousseau he received in words of authority the conception of the inherent dignity of the individual man. Through this conception science and speculation came to have a new value to Kant. They were no longer ends in themselves, but the means for moral development. The moral in its primacy over the intellectual came to be a permanent feature in Kant’s doctrine. His early Pietism was confirmed, and Rousseau replaced Newton in his regard.

5. The Skepticism of Hume. The influence of Hume’s skepticism was felt by Kant just before his eleven years of silence, when he became engaged in his construction of his critical problem. But Hume influenced Kant in a negative way. The classic and oft-quoted expression of Kant, that Hume awoke him from his “dogmatic slumber,” refers to the dogmatism of the empirical school to which Hume belonged, and not to that of the rationalistic school of Wolff. To Kant both empiricism and rationalism were dogmatic; the one because it assumed the validity of sensations, the other because it assumed the existence of innate ideas. Thus Hume effected a reaction in Kant against Hume’s own doctrine. But in thus reacting from Hume, Kant saw that the answer was to be found not in the rationalism of Wolff, but in an ideal conception of space and time. Hume’s influence was the last before Kant firmly established his theory of knowledge in his Critique of Pure Reason.

The Life and Writings of Kant (1724–1804). The external changes in the life of Immanuel Kant were the fewest possible. He was born at Königsberg in 1724; he went to the school of that city and then to its university, and then acted in the capacity of tutor in families in the province of Königsberg. He became privat-docent in the university at the age of thirty-one, and professor of logic and metaphysics at the age of forty-four. He was called to the University of Halle in 1778, but he refused to leave Königsberg. In fact, Kant never went outside the province, and but little outside the city. Nevertheless, in the eighties he saw himself become the most important figure in Königsberg, and in the nineties the most important power in German academic circles. In 1794 he came under the censure of the reactionary government of Frederick William II and “was obliged to refrain in the future from all public addresses on religion.” This was the only outer conflict in his life. In 1804, at the age of eighty, he died. The externals of his life were from the beginning to the end an undeviating routine,—his lectures, his daily walk, his dinner with friends, his hours of reflection upon his great problem. These have been made the subject of many descriptions.54

The life of Kant is notable because it is the history of an unusual singleness of devotion to the solution of a speculative problem. His youthful point of departure was the rationalism of Wolff; his point of attainment was the Critique of Pure Reason. Between these two points his history was a series of mental reversals. Kant spoke of his life as divided into two parts at the year 1770; his pre-critical and his critical periods. At that time there was a change in the form as well as the content of his writings. His pre-critical writings possess a graceful, flowing style; his critical works are heavy and artificial in their structure, and reveal the labor with which his thought tried to reconcile contending motifs. So far as the content of Kant’s thought is concerned the pre-critical period will be seen to fall into two subdivisions at the year 1760. Kant’s life may therefore be divided into three epochs: (1) 1724–1760, the period when he was a Wolffian rationalist; (2) 1760–1770, the period when he was an empirical skeptic; (3) 1770–1804, the period when he was a critical epistemologist.

In the first period he accepted the rationalism of Wolff, but his main interest, as shown by his writings, was in natural science. He was inspired by the natural philosophy of Newton, which, in the latter part of this period, led him to mistrust the metaphysics of Wolff. That is to say, he began to suspect that the mere logical operation of concepts by the “pure reason” could not be a statement about things in the real world. In the next ten years—his second period—he became convinced that the metaphysics of the rationalists was impossible, and yet that the metaphysics of the empirical school of the English was equally absurd. His writings during this time are more strictly devoted to questions of metaphysics and epistemology. Then came his critical period. This was inaugurated by his celebrated Dissertation of 1770, followed by a period of eleven years of literary silence, a silence broken by the publication of his Critique of Pure Reason in 1781. Between 1781 and 1790 appeared the more mature works from Kant’s pen. Among them were the Critique of Practical Reason (1788) and the Critique of Judgment (1790), formed on the model of the Critique of Pure Reason. Besides these, his minor writings were very numerous, and one notes an essay by him in the last year of his life. But the writings of Kant after 1790 treat in the main of the philosophy of law and conduct, and show themselves to be the writings of his declining years.

The Problem of Kant. The problem which Kant placed before himself was that of epistemology. Epistemology is the theory of knowledge, and Kant set to work to investigate the knowing process. The peculiar significance of Kant rests upon the fact that out of the various influences converging upon him and his time he matured a new conception of the problem and of the method of procedure of philosophy. He was convinced that the problem of his time was not one of metaphysical speculation, although he felt the value of such speculation in the regions of religion and morals. Yet he saw that the metaphysical rationalism of Wolff had proved itself inadequate because it was merely the logical operation of concepts, and had not dealt with real relations. He was equally sure that the empirical metaphysics of the Englishmen was inadequate because it was never certain of any truth. Rational metaphysics was logically true, but not real; empirical metaphysics was real enough, but never true. So Kant determined to find out the relation between the logical process of thought and the reality of things. He felt that the first problem in his time to be faced and settled was the problem of knowledge,—the epistemological problem. He planned to face later the metaphysical problem, but he delayed this until too late in his old age. The problem of Kant can be put in the simple question, What can we know? The metaphysical problem that he deferred was, What is real? Yet his problem was not nearly so simple as this statement would seem to make it; for the epistemological problem which he set himself was complicated by the Wolffian metaphysical dualism which he always presupposed. Since Kant agreed with the Wolffian dualism—the theory that a great gulf separates mind and matter—his query about knowledge was not the simple question, What can we know? but the longer question, What can we know about the external world?

The Method of Kant. There is bound up with the epistemological problem a new method of procedure in solving it. How shall we find out what we can know? Kant calls his method the critical method. It is not only a criticism in a general sense, in that it weighs carefully the conditions of knowledge. It is also criticism in the special sense of confining itself to a restricted field. Kant pointed out that two methods may be employed, the dogmatic and the transcendental. He asserted that the dogmatic method had been employed in the past and had proved itself fallacious. What is the dogmatic method? All philosophy was dogmatic to Kant which sought to find out what knowledge is true by showing how it originated and developed. Dogmatism is no solution; it is merely a psychological tracing of ideas to their sources. These sources will be either innate ideas, if we are rationalists, or sensations, if we are empiricists. The true method is the transcendental or critical method. What is this method? It is a study of the nature of the reason itself. It is an examination of the “pure reason” to see if its judgments have in any instance a universality beyond human experience, and yet are necessary to human experience. The logic of such judgments must be absolutely reliable; and yet at the same time the judgments must be applicable to the world of things. The method being transcendental, such judgments are transcendental; not because they transcend our experience, but because they are necessary to experience. The transcendental is not what is chronologically but what is rationally prior. The transcendental is the indispensable to knowledge. The critical method is the finding of this indispensable condition. Kant would search the whole field of the reason for this. Since to Kant thinking, feeling, and willing are the fundamental forms of the reason, he sought the realm of thought for the transcendental principles of knowledge, that of the will for the transcendental principles of morality, that of feeling for the transcendental principles of beauty.

The Threefold World55 of Kant—Subjective States, Things-in-Themselves, and Phenomena. In his search for those indispensable conditions of knowledge of the external world, Kant unfolds the threefold character of the realm of human life. To Wolff the world had been twofold. In other words, Wolff had conceived the world as dual, in which there was a correspondence, part by part, of independent reality to the states of consciousness. To Wolff reality is independent of consciousness, and yet we are conscious of that reality. Now Kant never gave up entirely the Wolffian dualism, but he came to see that in such a situation there could be no knowledge. For how can we be conscious of what is absolutely independent of us? Consequently Kant plundered the Wolffian worlds of independent realities to build up an intermediate world,—a world of phenomena. He dissolved the sharpness of Wolff’s dualism into a world with three divisions; and he gave to each division a new epistemological value. These were the realm of the subjective states or the inner consciousness of the individual, the world of phenomena or the realm of knowledge, and the world of absolute reality or that of things-in-themselves. The value of the world of phenomena consists in its being the realm of knowledge. The other two realms have values of their own, which we shall describe below.

Wolff’s twofold world may be thus compared with Kant’s threefold world:—

Wolff.	Kant.
1. Mind.	1. Subjective states.
	2. Phenomena—the realm of knowledge.
2. Matter.	3. Things-in-themselves.

1. The realm of subjective states evidently is not a realm of knowledge. For it is the realm of intuition and immediate apprehension of the individual’s own ideas and sensations; and this is not what we mean by knowledge. This subjective world is that in which I live alone. It is a realm of which nobody else is conscious, a realm which gives to me my individuality. The only connecting linkage between my various purely subjective states is the accidental order of time in which, empirically or by association, they occur. Animal intelligence possesses only such sense-perceptions and sensations, and these are modifications of its subjective consciousness. Such a mental constitution has not the capacity for knowledge, but only the haphazard association of ideas. Kant looked upon the content of subjective consciousness as the object only of psychological investigation.

2. The realm of things-in-themselves is not to Kant the realm of knowledge. By things-in-themselves Kant distinctly does not mean things-for-us, not material bodies, not nature objects. It must be remembered that Kant has plundered the material realm of the dualist. The things-in-themselves which are left behind as a residuum lie outside all sense-perception and so beyond all knowledge. A divine intelligence might have the things-in-themselves as objects of knowledge, but not we human beings. The thing-in-itself is the unknown and unknowable. But if this realm of things-in-themselves is so absolutely independent of us that we cannot in any way know it, how can we say that it exists? Kant replies to this: while we cannot say what a thing-in-itself is, we are obliged to say that it is. For although beyond even our sense-perception, it stands as a necessary postulate to perception, as a mere “problem.” Kant also calls things-in-themselves Noumena, and regards them as “limiting concepts” to the divine non-sensuous intelligence. Their reality is as little to be denied as affirmed.

3. Kant pointed out that between or beside the realm of subjectivity and that of the things-in-themselves lies the realm of human knowledge, which we in our every-day speech call physical nature, and to which he gave the name “the world of phenomena” or “the world of experience.” The subjective world is apprehended by the individual alone, the world of things-in-themselves is known by no human being, but the world of phenomena is the common object of knowledge of humanity. Phenomena are not things-in-themselves, but things-for-us; they are physical nature, an interrelated totality for us. They constitute not absolute reality, but a reality relative to us. Phenomena are experiences in their relations; such related experiences are objects of knowledge, and in their thoroughly organized and systematic form they constitute nature.

Thus the dualism which we ordinarily meet, like the “two world” theory of Wolff, has many differences from this critical theory of Kant with its threefold divisions of one world. One of the most important is that in Kant’s theory the correspondence between states of consciousness and reality has disappeared. Reality touches consciousness only at one point,—at that point where sensations arise. Sensations mark the boundary between unknown reality and conscious life. On the side of reality all is darkness; on the side of conscious life all is the creation of our complex synthetic activity. With the boundary line of sensation as a base, the two realms extend in opposite directions. In value the realm of our conscious life is only relative; that of reality or things-in-themselves is absolute.

The World of Knowledge. There is this to be observed about the threefold realm of Kant: the realm of subjectivity and that of knowledge together make up our conscious life. One is the realm of the conscious individual, and the other the realm of the consciousness of humanity. Kant conceived this further distinction between the two realms: in a purely subjective state the mind is entirely passive and its content is without control; in a state of knowing the mind is actively engaged in collecting and relating its ideas. This is called by Kant synthesis.

When Kant was formulating his problem, there gradually came to him in clearer outline the synthetic nature of the activity of the human reason. He felt more and more that the secret of the knowing process was to be explained by its function of combining many experiences into a unity. This conception of synthesis is what separates the Critique of Pure Reason from all the previous writings of Kant. Furthermore, the three books of the Critique are expositions of the different stages in which mental synthesis completes itself: in (1) perception, (2) understanding, and (3) reason. The knowing activity of man develops in these three different forms of synthesis, in which each lower stage is the content of the higher.

What, then, is the central factor in knowledge? It is the synthetic power of the mind. The mind is not merely passively aware of its sensations as they come seriatim, but it actively relates them and holds them together. The mind is a dynamic agent whose activity consists in synthesizing in the present moment its experiences of the past. The human mind is not like a curtain upon which stereopticon pictures appear and then disappear in turn. It retains its pictures, although they are no longer being thrown upon the screen. Suppose we hear the ticking of a clock. Now if we had no synthetic power, all we should apprehend would be one, one, one,—and so on. But we do have synthetic power, and we say one, two, three, and so on. We count in a series in which each term includes the preceding term. Two includes one, and three includes two, etc. This is knowledge. It is cumulative experience. The experience of twenty animals, each having one experience, is not the same as the experience of one man having twenty experiences. In vain would nature act on man if the mind of man through memory and imagination did not carry over experiences. So the important thing is not what happens, but what power the human mind has. Knowledge, then, to Kant is the unifying of the manifold.

There are, therefore, two aspects to knowledge; the passive sensations and the active power of synthesis. Sensations, on the one hand, are the raw material out of which reason through its various forms creates the finished fabric of knowledge. Sensations are the content of knowledge. On the other hand, there is the active unifying power of the reason. Knowledge consists of sensations and synthesis in conjunction. Reason alone deals with “thought relations” or imaginations, whenever it tries to treat objects of which sensations are not the raw material. Sensations alone, however, are only subjective states. The oft-quoted sayings of Kant, that “Only in experience is the truth,” and that “Conception without perception is empty, perception without conception is blind,” refer to the restriction of knowledge to the sense-materials and to the synthetic function of the reason.

The Place of Synthesis in Knowledge. What position does synthesis occupy in the total process of knowledge? Is synthesis one of the factors or elements of knowledge? Is synthesis on the same level with the sensations, the feelings, the imaginations? No, it is very different. The synthesis that Kant is describing is not the product or conclusion from an inference. Kant does not mean by synthesis the combination of facts as a result, such as a biologist might make in framing the law of the habits of animals from his observation of them. The synthesis that Kant is talking about is not so much the result of combining experiences as the act of combining them. The frame of the unified manifold, the law of its unification, the act of binding the isolated experiences together is synthesis. Synthesis occupies a higher level than the elements of knowledge or knowledge itself. Synthesis is the knowing process rather than the known product. It is constitutive; it is creative; it conditions experience and puts the material of experience together. It must not be thought to be a voluntary act of the mind, which the mind will or will not do, as it pleases. When the mind acts, it synthesizes.

Furthermore, the synthetic functioning of all human minds everywhere is the same. However much their sensations differ, they combine and orderly arrange their sense-materials in the same ways. The synthesis of the human mind is the source of the universality belonging to knowledge; the sensations, the “given,” are the source of the difference in knowledge. Knowledge is the result of minds that function in absolutely the same ways; and we should never have knowledge if the order and linkage of the world depended on the accident of experience. Take, for example, such laws as those of mathematics or the physical law of cause. These are the same for everybody. They are universal laws. The ordinary conception of them as independent principles of an independent nature world will not account for their necessity for everybody and their universality. As independent principles they would differ for different peoples just as sensations differ. In that case we should have no knowledge. Human beings could not then think about the same things, nor reason under the same guiding principles. However, we do think alike, we have the same geometry, the same physical laws, the same time-estimates; and simply because we function alike synthetically. Knowledge is thus the common possession of humanity because the synthetic functioning of the different individual men is identically the same.

A very good way to get at Kant’s central principle of synthesis is to draw this picture. Suppose that besides the race of human beings with its own peculiar way of ordering its world, there were a race of angels endowed with its own powers, another of hobgoblins likewise endowed with its own powers, and so on to x, y, and z races—any number you please. What would be the situation? In the first place, each one of the groups would be absolutely isolated from each of the others. No one would have the power to know even the existence of the others. No one race would even have anything in common with the others. The world of each would be different. In the next place each would be trying to interpret reality, and in doing so, each would construct and order a world of reality of its own. The members of each race would have a world in common and the members would know one another. But that is all. The members of each race would not be able to get outside their own powers of synthesis. In Holy Writ the home of the angels has been sometimes described as having no time and space, but this means only that space and time are aspects of our mental synthesis and not of theirs. We live in our world of our interpretative construction of reality, and they in theirs. The same would have to be said of x, y, and z. None would live in a world of absolute reality. But each would live in a world made different from all the other worlds by the differing mental powers of each race. Yet the members of each race would inhabit a world in common because the individuals of each had common mental powers. The particular world that human beings inhabit is called physical nature, whose laws are known as the laws of science. How can it be one world in which so many millions of different human beings live? Because these millions of human beings are under the same fundamental rational laws, and they construct the world in a common fashion. The laws of nature are, after all, the laws of our own minds. They are the laws of reason. The laws of nature are not the laws of absolute reality, but the laws of the human interpretation of reality. All the linkage of facts, all the law and order of our universe, all the combination of the variety of objects of knowledge—in a word, the entire body of science or the world of physical nature is a human mental synthesis. Does independent absolute reality exist? Yes; but it exists behind the scenes for us as for the angels. Mental synthesis is constitutive of the world in which we are actually engaged—mental synthesis is shot through and through all our experiences. Mental synthesis is the framework of the universe, and therefore Kant says, “The world is my representation.”

The Judgments Indispensable to Human Knowledge. It will be seen from the above discussion that Kant does not believe that an idea or a sensation taken by itself constitutes knowledge. Knowledge consists of sensations framed together in a synthesis. That is, ideas must be taken together with other ideas. This is called in grammar a proposition, having a subject and a predicate. In logic it is called a judgment. The only way a human being can express knowledge is in the form of judgments, but all judgments of human beings are not necessarily knowledge.

Judgments are divided by Kant into two large classes,—analytic and synthetic. The large class of analytic judgments are not expressions of knowledge. What is an analytic judgment? An analytic judgment merely expresses in the predicate something that is contained in the usual meaning of the subject. Such a judgment articulates the meaning of an idea by emphasizing some of its well-known attributes. Thus we say, “Gold is yellow.” Such a statement about “gold” does not show any knowledge. It is called sometimes an explicative statement. It is tautologous, but not on that account trivial. Let us look then to synthetic judgments to see if they express knowledge. But first, what is a synthetic judgment? A synthetic judgment is one in which the predicate is not contained in the usual meaning of the subject. It is a statement of something new about the subject in hand. For example, the judgment, “The watch is yellow” is a synthetic judgment because the predicate “yellow” is not a necessary part of the meaning of “watch.” A synthetic judgment therefore brings two ideas together in a new relation. It thereby enriches knowledge and is the expression of discovery. The synthetic judgment is often called ampliative. (The double meaning which Kant gives the term “synthetic” need not confuse us. Synthesis is used by Kant to mean the framing constitution of the mind, and also as one of the results of the activity of the mind, i. e. a class of judgments. In the first sense all judgments, both analytic and synthetic, are expressions of synthesis.)

Are all synthetic judgments expressions of knowledge? Kant replies that they certainly are not. He points out that there are two classes of synthetic judgments: one class he calls a posteriori and the other a priori. By a posteriori he means judgments founded in some sense-perception, which are particular judgments or judgments that are inferences from a greater or less induction of sense-perceptions. For example, if I say, “To-day is warm,” or that “Swans, so far as I have observed, are white,” I am making a synthetic judgment, because I am joining two ideas in a new relation, and I am also making an a posteriori judgment, because it is a statement founded upon sense-perception. Now Kant rules such judgments out from those that constitute true knowledge. This would rule out even empirical generalizations of high probability, such as “The sun rises in the east.” A posteriori judgments, or those founded on experience, however large, do not give us knowledge, but merely probability. The cases upon which such judgments are founded are always limited, and there may be exceptions beyond our observation.

The only kind of judgments that are the expression of true knowledge must, therefore, be synthetic judgments that are a priori. That is to say, they must express some new relation between ideas that is also universally and necessarily true. By a priori Kant means the universal and necessary; and, furthermore, he maintains that the universal and necessary, and nothing else, constitutes knowledge. He points out that we make such judgments. When we say that the three angles of a triangle equal two right angles, or that every event has a cause, we are saying something universal and necessary, something not founded on experience. No one would admit that there were exceptions to these propositions. The question, then, that Kant tries to answer in his Critique of Pure Reason is, How are synthetic judgments a priori possible? Or since to Kant knowledge consists of synthetic judgments a priori, under what conditions is knowledge possible?56

For the sake of clearness, let us state this problem of Kant in another way. It is the nature of man to try by mere thinking to discover the nature of reality. The dogmatic school of Rationalists had attempted, without calling in experience to its aid, to weave out of pure thought answers to the questions about God, immortality, and nature. It had maintained that clear and distinct notions have a reality corresponding to them, and are therefore real. Judgments formed in this way are analytic a priori; but it is evident that while such analyses of thought have a cogency for thought, they do not necessarily have a corresponding reality. On the other hand, conclusions based on experience have a kind of validity for the real world, but they yield no certain truth about it. These are synthetic judgments a posteriori. If Hume is right in saying that these are the only judgments dealing with nature, then we have no certain truth about nature. They give generalizations that are useful on the whole, but their conclusions range only from possibility to high probability, and never reach certainty. Besides (1) conceptual knowledge and (2) “knowledge of matters of fact,” Kant pointed out that there is a third kind. This is the only valid kind. This knowledge is based on synthetic judgments a priori. Such knowledge arises independently of experience, i. e. is a priori, and yet is valid for experience, i. e. is synthetic. Hume’s statement that such knowledge is synthetic a posteriori is not accepted by Kant. Kant is, therefore, bound to show how this third class of synthetic judgments a priori is possible, and how pure thought can be binding on experience.

The Proof of the Validity of Human Knowledge. If we turn now to review what we have said about Kant, we find that he undertakes to solve the problem, How can we know? by a critical study of the forms of the reason. We have found that the reason is essentially a synthetic power, and is the framework of the world of phenomena to which knowledge is limited. Knowledge is the complex thing, consisting of sensations as its woof and synthesis as its warp. To answer the question, Under what conditions is knowledge possible? we must study not sensations, but synthesis in its several forms. If Kant can show that the mind furnishes the a priori, that is, the universal and necessary forms to knowledge, he thinks he has proved his case. He has then explained why human knowledge is valid and thus proved that human knowledge is valid. Now Kant tries to show what the special a priori forms of knowledge are and in what the validity of such forms consists. In the first book of the Critique of Pure Reason, the Æsthetic, he undertakes to show what the a priori forms of mathematics are and how they make knowledge valid by being forms of mental synthesis. In the next part of the Critique, the Analytic, he tries to show what the a priori forms of the knowledge of physical science are and how they make physical science valid and objective. In the last part, the Dialectic, he discusses the a priori forms of the reason and shows why they have no validity in knowledge. These are three stages in which the knowing activity develops as three different forms of synthesis. The stages are perception, understanding, and reason. Each higher stage has the lower as its content. Finished knowledge involves perceptions, reproductions in the understanding, and a recognition of the whole by a thinking subject. Perception, understanding, and reason are not separate acts, but different levels of one consciousness. These will be taken up in succession.

1. In What does the Validity of Sense-Perception Consist? Kant points out:

(1) Sense-perception has (a) a content of sense qualities, like sound, color, etc., and (b) the relations of space and time.

(2) Space and time originally belong to the subject as its forms of sense-perception, and are not introduced from without by experience.

(3) By means of space and time a priori knowledge is possible.

If there is any validity in perceptual knowledge, it depends upon the constitution of space and time; not upon the character of the empirical content, or the sensations. The question about the validity of sense-perception, then, is a question about the reliability of mathematics.

There are two elements in sense-perception: a necessary and constant, and a changing and accidental. Space and time are the constant element. They are homogeneous, and always one and the same in quality. They are unities, for there is only one space and one time, and the many spaces and times are only divisions of this oneness. All the differences in space and time are due to the relation and movements of bodies, and are not inherent in space and time themselves. How is this unity and homogeneity of space and time to be explained? By assuming that space and time are original and uniform functions of perception, the forms of perception, the ways of apprehension, the “prehensile organs of our sensibility.” They are the ways in which we synthesize on the lower level of consciousness. If they were given in experience, there is no reason why the several spaces and times should not be intrinsically different, like different bodies with different qualities. However, by conceiving them to be mental syntheses in the level of perception, they explain the universality of the laws of mathematics. They are the colored spectacles that all human beings wear; or, to use another figure, they are the mould into which all sensations are run. Being the unchangeable forms of our sensuous receptivity, they have a validity for the entire compass of perception. They are universal because one experience of space and time is valid for all spaces and times; they are necessary because we cannot think of objects apart from them; they are perceptual syntheses because they increase knowledge. Of course we are unconscious of this perceptual synthesis of the sensory elements in space and time. The process takes place automatically. We can nevertheless analyze the process after it has taken place, and speak of the sensations as the materials of knowledge, and the forms of space and time as the a priori elements. But in actual conscious experience, sensations never come to us in their rawness. They are never turned over to the understanding unless they bear the stamp of space and time. The process of knowledge, therefore, starts with complex material—complex because it has been synthesized below consciousness. In other words, perceptions come into the process of knowledge with two aspects: (1) their permanent and necessary form; and (2) their accidental and changing content.

2. In What does the Validity of the Understanding Consist? Kant’s discussion of the synthesis of the understanding is given in the Analytic, the second part of his Critique. His treatment of the understanding is similar to that of perception. The understanding, be it remembered, is regarded by Kant as the second stage in the process of a complete synthesis of knowledge. It is synthesis on a higher level than perception. Indeed, perception is the material which the understanding synthesizes. As in the Æsthetic Kant seeks to show: (1) the a priori factors of the understanding and (2) that these a priori factors give to knowledge its validity. The unifying principle of perception is the mathematical; but physical nature, which is the subject-matter of the study of the understanding, is more than mathematical, more than an aggregate of space and time forms, more than shapes and motions. Nature exists as a connected system of substances, causes, etc. Natural science possesses besides its mathematical basis a number of general a priori principles for the validity of its conclusions.

Kant’s task was therefore only begun by showing that perception possesses the universal and synthetic principles of space and time. Perception is only the beginning of knowledge. It is not knowledge, but only subjective consciousness. On the other hand, the understanding is the faculty of knowledge, and therefore Kant seeks to point out its a priori or universal elements, and by their presence prove its validity.

Since the days of Aristotle the general terms used in reasoning have been called categories. Any class-term or genus may be called a category. There are certain summa genera, the most extensive classes or classes with the lowest connotation, that have been traditionally known as categories, because everything that can be affirmed in a judgment must come under some one or other of them. Aristotle names ten,—substance, quality, quantity, etc. But these Aristotelian categories are classes of analytical relations, such as formal logic treats. They are the classes of the attributes and relations into which objects may be analyzed. These evidently are not what Kant is seeking. He is in search of synthetic categories. He is looking for the synthetic forms of the understanding itself, which transform perceptions into objects of knowledge. He is not looking merely for abstract conceptions. For ideas become nature objects only when they are thought as things with qualities universal to every human mind. The understanding creates out of the perceptions the objects of thought which form the nature-world; and the categories of the understanding are the constitutive principles of such objects. The categories are the relating forms of synthesis through which objects arise. The most difficult part of the Critique is called the “Deduction of the Categories,” in which Kant attempts to derive the synthetic forms of the understanding from the various kinds of judgment. Kant’s list is curious but unimportant, and only two of these categories are useful,—substance and cause. He divides the categories into four general kinds and enumerates three categories of each of these kinds, as follows:—

Categories of Quantity,—Unity, Plurality, Totality.

Categories of Quality,—Reality, Negation, Limitation.

Categories of Relation,—Substance, Cause, Reciprocity.

Categories of Modality,—Possibility, Existence, Necessity.

These categories occupy the same position in the understanding that space and time do in the perception,—they are the a priori principles. In respect to them the perceptions are the a posteriori material. The categories are pure, innate, and transcendental. They are the inner nature of the understanding. Thus the objects of the understanding contain both a priori and a posteriori factors, and are syntheses of manifolds. Perception synthesizes sensations, while the understanding synthesizes perceptions, and states the synthesis in the form of a judgment.

Having named the a priori forms of the understanding, how does Kant show that by their means our knowledge of nature has validity? Because when the understanding functions, it prescribes these forms to perception. Impressions would remain vague and formless, if we did not think them; by means of thought we weld impressions into objects and give them a coherent reality. This is exactly what is meant by understanding. If nature were an independent thing and prescribed laws to the understanding, the laws would never be universal and necessary. The universality of the laws of nature can be explained only by supposing that the understanding prescribes its laws to nature, not to nature as a Thing-in-Itself, but only so far as it appears in sense-perception. Universal and necessary knowledge of nature is possible only if the connections and relations of nature are absolutely identical with the modes of thought. The categories of the understanding have objective validity, therefore, because the laws of the understanding are the fundamental laws of nature. The understanding has given such laws to nature. A priori and therefore universal and necessary, synthetic and therefore creative, the world consists of objects under laws of the understanding. There are as many kinds of natural objects as there are categories of the understanding.

If we will examine what we call the world of nature, we shall find that many of its objects have never been perceived. Man has only partly explored the earth, and there are vast regions in space that he has never seen. He has never seen the South Pole, and the North Pole only recently; he has never seen the other side of the moon, and there are myriads of stars beyond even the reach of his telescope. These are not perceptible things, and yet they are the objects of the understanding—objects of knowledge. How is it possible? It would not be possible if the laws of nature were limited to the empirically perceived facts. It is possible because the laws of the understanding are the laws of nature and apply everywhere, whether the thing is actually perceived or not. The moon must have another side because the human understanding conceives all substances in this way; the law of cause and effect obtains beyond the stars, and at the South Pole, even though they have never been perceived. The world of physical objects, or in other words the world of objects of the understanding, consists of both possible and actually perceived objects. If the laws of nature were prescribed by nature to the mind, then the world of objects would consist only of actually perceived objects.

But look at the world of nature a little more closely. It is one whole world with very many things in it. Why is this the case? Would it ever be so if our knowledge of the world was simply a reproduction of what the world presented to us? Of course not. There would be as many different worlds as there are human beings. The wholeness, the oneness of our world of many things to many individuals indicates not only that the understanding is the source of the laws of the world, but also that the faculties of understanding in all the millions of human beings have a transcendental unity. Knowledge has therefore a stronger proof of its validity, since what is knowledge for one human being is knowledge for all. Every individual man is conscious of the contrast between his own subjective world and the world of knowledge which he shares with other men. His own ideas have a movement of their own and have no validity beyond themselves; the ideas which he shares with others, however, are valid for all others because these ideas are beyond the control of any one man. Each individual man has to acknowledge this control of his knowledge as residing in something beyond himself. The categories of each man’s understanding coöperate exactly with those of every other man. The individual man is not actually conscious of this process of coöperation in experience, but he accepts the objective necessity of it.

The individual consciousness is not therefore the creator of the objects of knowledge; rather consciousness in general—the consciousness of humanity—is the creator. Kant is not a solipsist, but an idealist. A higher consciousness, a super-conscious Self, must be assumed to explain the compactness of human knowledge. Kant does not call this super-conscious Self the “soul” or “spirit,” but the “I think” or the “transcendental ego,” or by the more clumsy phrase “the transcendental unity of apperception.” He contrasts it with what he calls the “empirical ego” on the ground that it is the ego always identical with itself, rather than the Self at this or that particular moment. It is the Self as thinker rather than the Self as thought about. The super-conscious Self is always self-active and never dependent upon empirical conditions. It must be accepted as the postulate of all knowledge. It is the universal Self, and through it the categories of the human understanding become universalized. Just as space and time are the unifying forms of synthetic consciousness on its lower level; just as the categories of the understanding are the unifying forms of the synthetic consciousness on a higher level; so the universal Self must be postulated to explain the universality of the categories. It is a postulate only because it, not known in experience, is necessary to explain the unity of knowledge. This theoretical conception of the Self by Kant is thus very different from the traditional notion of the soul.

Has the Reason by Itself any Validity? When Kant calls his criticism the Critique of Pure Reason, he uses the term “Reason” in a wide sense as the whole knowing process. In the Dialectic he treats the Reason in a narrow sense, as if it were a special faculty like the perception or understanding. This is, of course, a confusing use of terms, like his use of the term “Synthesis”; but it should cause no difficulty provided the two uses are known beforehand. The term “Ideas” is also used in two senses. In this place it has a special use. While usually an idea means any thought, here it means the synthetic form of the special faculty of the reason, just as the categories are the form of the understanding, and space and time the form of sense-perception. The synthetic forms of the Reason are the three Ideas, viz., God, the soul, and the totality of the universe.

What is the office of this special faculty of the Reason and its Idea-forms? They represent Kant’s way of stating the natural tendency of the human mind to get from its knowledge the greatest possible unity with the greatest possible extension. Consciousness is a synthesis which is never satisfied in being partial and incomplete. The partial syntheses of its faculties of perception and understanding do not satisfy it. Perception and understanding tell us nothing about God, about the soul, and about the totality of the universe, for these faculties are fettered to experience. Yet God, the soul, and the totality of the universe are very important matters. So the Reason leaps over the boundaries of experience, and thinks it is justified in poaching in the territory forbidden to knowledge. The Reason is not content with the partial and relational knowledge of mathematics and of physical science, but it would deal with the unrelated and the unconditioned. Indeed, we need only search our own minds to see how true Kant is to fact. We find that we ourselves are not satisfied with conditioned things, which must be explained by other conditioned things. On the contrary, we long to know the absolutely unconditioned, which alone will explain all conditions. We are forever seeking to make our synthesis complete, and to render a rational and complete account of what is nevertheless impossible to our knowledge.

Now it is evident that the Ideas of the Reason are not indispensable to knowledge in the sense that the categories of the understanding and the forms of sense perception are indispensable. Cause, time, and space enter into all knowledge. Physical and mathematical laws exist as facts, and need no proof for their existence. Kant asked about them, “How are synthetic a priori judgments possible?” But concerning the judgments of the Reason, he asks a different question: not How are they possible, but Are they possible?

The Reason and its three Ideas give what Kant calls transcendent knowledge in distinction from the transcendental knowledge of the understanding and its categories. By transcendent knowledge he means that which is beyond the limits of possible experience; while transcendental knowledge refers to knowledge about the necessary principles of experience. Kant, however, is willing to acknowledge that the Ideas of the Reason have a legitimate use. They are “regulative principles” in that, by showing what our limitations are, they also show that human knowledge is not the final goal. Their illegitimate use appears when they make a show of being true knowledge. Both science and theology will be the gainers when the Ideas are no longer used illegitimately. Kant says that he has destroyed knowledge of God and the soul “in order to make room for faith.”

The Idea of the Soul. Rational psychology had taught that the soul had direct and intuitive knowledge of itself. From the time when Descartes formulated his famous “Cogito ergo sum,” this conception of self-consciousness has been popular. I can have myself as the direct object of my own thought. Upon the basis of such assumed intuitive knowledge that each soul has of itself, the Rationalists had ascribed the qualities of simplicity, substantiality, spirituality, and immortality to the soul.

Kant denies that we have any such self-knowledge. If we turn back to his definition of knowledge we find it to be a synthesis of a manifold. Knowledge, to be knowledge, must (1) be based upon sensations, and on that account (2) consist only of phenomena. The soul is not phenomenal, but the deepest kind of reality. How can I have knowledge of my soul? The soul is spiritual and not phenomenal, even according to the Rationalistic philosophy. Therefore the soul is precluded from being an object of knowledge. Furthermore the Rationalists’ conception of the soul as simple and immortal would make it an impossible object of knowledge. An object of knowledge is not simple, but is the unity of a manifold. The unifying or synthesizing function is not an object to itself. Sensations are synthesized by space and time into perceptions; but space and time are not objects for the sensations. In understanding, therefore, the “I think,” which synthesizes the perceptions into judgment, cannot be an object for the understanding.

Kant points out that we must be careful to distinguish between the transcendental and the empirical ego. We have referred to this distinction already. In Kant’s criticism of knowledge he maintained that there must be postulated a “synthetic unity of apperception,” if knowledge is possible. But such an ego is only a postulate; we can have no knowledge of it nor can we say what it is. We know that the immediacy of experience or the sameness of knowledge from moment to moment demands this. This is the transcendental ego, a kind of universal synthetic background.

But this is different from the empirical ego, which I can know as an object of experience. The empirical ego is what I can know of myself at any time—a group of sensations, feelings, or thoughts. Now such groups change from moment to moment. My knowledge of myself consists only of my momentary, changing self. This changing self is not the immortal, simple, and identical soul of which the Rationalists have been speaking. The empirical self is complex and transitory; it is an object of knowledge, and it is not therefore the same as the immortal soul. “I think I” is impossible. “I think me” is possible. To make the “I” an object is to commit a fallacy.

The Idea of the Universe. The contradiction in reasoning about matters beyond the test of experience appears sharply with reference to problems about the world as a totality. The inherent self-contradiction of the reason attracted Kant’s attention very early with reference to the problems of infinity. Such self-contradictions were put into final shape by Kant in the Critique in the four following so-called antinomies:—

(1) The antinomy of creation. Thesis: The world must have a beginning in time and be inclosed in finite space. Antithesis: The world is eternal and infinite.

(2) The antinomy of immortality (or the simple). Thesis: The world is ultimately divisible into simple parts which cannot be further divided. Antithesis: The world is composed of parts subject to further division, and no simple thing exists in the world.

(3) The antinomy of freedom. Thesis: There is freedom; there are phenomena that cannot be accounted for by necessity. Antithesis: There is no freedom, but everything takes place entirely according to the necessary laws of nature.

(4) The antinomy of theology. Thesis: There is a necessary being either as part or as cause of the world. Antithesis: There exists neither within nor without the world an absolutely necessary being.

Critics have pointed out that these problems as thus stated by Kant are not altogether cosmological problems, but include the contradictions of psychology and theology; that is, all the contradictions of the Reason when it is used dialectically. They show how both Rationalism and Empiricism, as metaphysical theories, are in their nature contradictory. When the universe is treated as an object of knowledge, contradictory propositions can be maintained. The contradictories are both proved and refuted. In respect to the first two antinomies, both theses and antitheses are false; in respect to the last two, both theses and antitheses may be true, if they refer to different worlds. If the Ideas are applied only to the world of phenomena, they involve inexplicable contradiction. The Idea of free will and unconditioned being may apply to the world of Noumena; while the Idea of necessity and conditioned being may apply to the world of phenomena.

The Idea of God. The Idea of the soul involves us in a paralogism, the Idea of the universe as a whole involves us in inextricable difficulties and contradictions; the Idea of God cannot be demonstrated. Kant does not deny that God exists. He merely maintains that we cannot make God an object of knowledge. The Idea of God is to Kant the expression of the need of the Reason for a perfect unity.

In one of his earlier writings Kant had constructed a conception of God, which is the same as appears in the Critique. God, purely as a conception, is constructed by Kant as the sum total of reality, the ens realissimum, who so includes all finite qualities in Himself that they do not limit Him. He is the primal cause of the possibility of all being. Now, can such an Idea have objective validity? No; the Idea of a sum total of all that is conceivable is not an object of possible experience. Only particular things or phenomena are realities for us. God as the transcending total of particular things can have only a conceptual reality and a validity for thought. The total has the reality that any idea has. This is Kant’s general criticism of the dialectic Idea of God.

But the general conception of God had played so important a part in traditional philosophy that Kant felt it necessary to examine the three important intellectual proofs for His existence in order to show their falsity.

He takes up first the ontological proof of God’s existence, which originated with St. Anselm and had been accepted by the Rationalists. The Idea of God is the idea of a perfect being. A being would not be perfect who did not exist. Therefore the Idea of a perfect being must include the quality “existence” among its predicates. The essence of God must involve His existence, because the unreality of the ens realissimum cannot be thought. Kant replies thus: “Being is no real predicate.” It is not a quality like love, power, or goodness, for it adds nothing to the content of the subject. “A hundred dollars contains no more content than a hundred possible or conceptual dollars.” We cannot reason from the concept of the actual to its existence. The only test of actuality is perception.

The cosmological proof, which Kant examines next, is an argument from the existence of contingent phenomena to the existence of an unconditioned reality. There must be some uncaused cause of existing caused phenomena. Kant’s reply is this: Cause has no meaning if it is applied beyond the bounds of experience. Within experience all causes are the results of causes, and therefore an uncaused cause is a contradiction in terms. Every existing thing is contingent. A necessary being can be only a thought, and would not be powerful. It would not be as powerful as a very great finite being which had existence.

The physico-teleological argument comes next under Kant’s criticism. This argument is based upon the inference that intelligent design found in nature implies an intelligent designer of nature. Kant replies as follows: Even granting that the world exhibits the design of beauty, goodness, and purpose in its construction, such a beautiful, good, and purposeful world would only prove the existence of an architect and not the existence of a creator. Kant points out, however, that this proof is the oldest, clearest, and the most popular; and he thinks it deserves to be treated with respect on that account. The wonder and magnificence of nature must free man from the oppression of any subtle argument against the significance of nature. Nevertheless Kant feels that this proof lacks intellectual cogency; for it is possible that nature is freely acting and has power within itself.

The conclusion of the Dialectic, in which the Reason attempts through its Ideas to soar beyond experience, is that such speculation has never added to our knowledge. Mere conceptual thought cannot be knowledge of the reality of the soul, God, and the world. Still, the Ideas of the reason are an integral part of the human mind, and they must have their purpose. They cannot be verified by experience, in which alone is truth, but they can regulate experience. They are “regulative Ideas” in that our experience is better governed if we act as if there were a soul, as if God existed, and as if the world were a totality of related things. Moreover, while speculation cannot prove the existence of God, the immortality of the soul, and the freedom of the will, atheistic speculation is unable to prove the contrary of all these propositions. The Ideas of the Reason clear the way for faith based on morality.

Conclusion. The Critique of Pure Reason is what its name implies,—a criticism of our conscious powers. It points out the limits and extent of human knowledge. In one sense, it is constructive; for it establishes against skepticism the conclusion that knowledge has a validity within its own limits. In another sense, it is destructive; for it shows against dogmatism how futile our intellectual striving is to explore many regions that have been considered the proper realm of knowledge. No knowledge is possible that is transcendent—no knowledge beyond the limits of experience. Experience ties our mental powers to itself. Experience is the boundary of the understanding. Reality, the Things-in-Themselves, are unknown and unknowable. But transcendental knowledge is possible. Within experience there are the transcendental factors that on the one hand transform sensations into phenomena, and on the other give to these phenomena a validity for all mankind. These transcendental factors make knowledge reliable, but they add not one whit to its content. On account of these transcendental factors we can be rational with one another and members of one world of humanity. The value of knowledge is not lessened, but is defined. Our world of phenomenal existence is now accurately assessed as a world of relative reality. It is placed in its proper perspective. It is seen as our own interpretation of what is really real. This is very important; for although the restricted form of our mental powers withholds us from knowing reality, we may nevertheless think it. The pure intellection of reality will be of value, if in some other way its contents can be assured. Kant now points out that this assurance is found in the moral will.

The Problem of the Critique of Practical Reason: The Ethics of Kant. “Two things fill the mind with ever new and increasing admiration and awe, the oftener and the longer we reflect upon them: the starry heavens above and the moral law within.” In this classic sentence Kant showed that he had no desire to humiliate the theoretical reason, which is the understanding. He was merely assigning it to its place among the powers of man, in order that it might do its proper work more efficiently. The world of morality and the starry heaven impressed Kant equally. Kant would not have the understanding chasing will-o’-the-wisps. After his criticism of the understanding he turned to the will, or as he calls it the practical reason, and criticized its functions and scope. This ethical teaching of Kant appears in his Metaphysic of Morality and in the Critique of Practical Reason. His early Pietistic education, his reading of Rousseau, his study of the English moralists, influenced his theory of morals; while his investigations into the history of civilization, his theoretical philosophy, and his independent analysis of the ethical feeling marked the route which his ethical development took. The world of morality to Kant has primacy. In his theory it is the real world, for compared to it the world of scientific phenomena, the world of the theoretical reason, is relative.

The central idea in Kant’s theory of morals is that rational spontaneity is exactly the same as freedom. This contrasts his theory with Hedonism. The value of man’s life depends on what he does spontaneously, not on what happens to him. This idea of freedom is the central thought in all Kant’s discussions of society. In his theory of government the republic is to be preferred to the monarchy, because of the opportunity to its citizens of spontaneous freedom; in religion the true church is composed of free beings worshiping God freely; in education self-activity is the sole principle of growth. Ethics is a system of the pure rational laws of freedom, just as science is a system of the pure rational laws of nature. If ethics has real validity its laws must be, as in science, a priori or derived from the reason itself, and synthetic or applicable to experience everywhere. If the moral law be valid it must be indifferent as to its content, and yet valid for all content irrespectively. The source of the principle of morals is thus the same as that of science: it is a priori. The principle of morals is universal in its application to experience, just as the a priori synthesis of knowledge is. However, just at that point the difference is to be seen between the foundation of science and that of morals—between the reason as pure and the reason as practical. Reason in the form of knowledge is restricted to experience; but reason in the form of the will, while applicable to experience, is not restricted to experience. If the understanding is without the content of experience, it is empty and useless. The understanding must always be a synthesis of a manifold. On the other hand, the practical reason needs no content. It is sufficient in itself. It need not be obeyed anywhere nor have any concrete content in the phenomenal world. It has no reference to what is but to what ought to be. The world of morality and the world of phenomena are different worlds. The world of morality is absolute reality, while the world of knowledge is only relative. The world of morality is the unconditioned, while that of knowledge is conditioned by experience. Morality applies not only to human beings, but to all rational beings, if any other rational beings exist. Knowledge, however, belongs to human beings alone. The moral law has not its home in the empirical, but in the transcendent, intelligible world, which to knowledge would be the world of Things-in-Themselves.

The Moral Law and the Two Questions concerning It. The questions of the Critique of Practical Reason are the same as those of the Dialectic: (1) Is there any a priori synthesis? This is not the question of the Analytic, which is, How is an a priori synthesis possible? (2) Can the human being be moral and still be a part of the world of phenomena and necessity? We shall now comment on the first of these problems. If the will has validity, it must be the expression of some universal and necessary principle. Can we find any such a priori principle in our consciousness?

1. The First Question concerning the Moral Law. If we search our consciousness, we shall find that there are two classes of incentives to action. The first are called the inclinations, or perhaps better the impulses. We may will because we desire to gain something, of use, pleasure, perfection, etc. Such an act of will is dependent upon the object that arouses it. Such an act of will would not be an example for any one else; for the circumstances that called it forth would be likely to be different in each case. For example, there is no consensus as to pleasure among individual men; and what is pleasant to one is unpleasant to another. The same is true about objects of use and ambition. In all these matters judgment does not help us in making our selection, for people who are the most discriminating often are the most unhappy and useless. All these things are indeed goods, but they are goods for the moment—goods that are dependent on something else, and not goods in themselves. They are legitimate ends enough, but they are so transitory that they cannot be valid. It is evident that when the will is governed by inclination, it is governed by an empirical (a posteriori), and not by a universal and necessary (a priori) principle. Such empirical principles are called by Kant hypothetical imperatives.

Let us look to the reason itself to see if the principle of its practice lies there; for it is certain that we shall not find the principle of universal validity for our will among our impulses. The reason is a spontaneous synthesis. It is a fact that any one may verify who will search his consciousness—that man may will from reason. The will may be impelled from within, and need not be compelled from without. The will may be an imperative in itself, proclaiming its right because it is reasonable, justifying itself because it is reasonable, functioning because it is the function of reason. Then is the will the expression of reason. It is the reason in practice. The will is unconditioned and free because it is the unconditioned reason acting. It is then autonomous. It has then validity because the reason is universal and necessary. This kind of willing Kant calls the categorical imperative. It is the moral law. It is a law unto itself, and it is the only basis for morality because it is the universally valid reason.

The categorical imperative is unique—there is nothing like it in human nature. It is the one kind of willing that has absolute validity; and that is because it is unique in having itself for its own end. The conscience may be said to be its expression in the individual. Kant formulates the valid command of the moral law as, “Act as if the maxim from which you act were to become through your will a universal law of nature.” The various maxims of morality, like “Thou shalt not lie,” occupy the same position to the will that the categories do to the understanding. They are the forms of the moral will. Actions should proceed from maxims rather than from impulses, and the moral maxims are adapted for all beings who act rationally. A specific act may become good because the moral law, that inspires it, is good. Nevertheless “nothing can possibly be conceived in the world or even out of it, which can be called good without qualification, except a good will.” The virtues or the gifts of fortune may be good and desirable; they may also be evil and mischievous, if they are not the expression of the moral will.

2. The Second Question concerning the Moral Law. This leads us to the answer to the second question, How can such a purely necessary and universal principle be effective in human life? Of what service to man is a principle so formal that if the inclinations coöperate with it, the act is no longer moral? The moral law is not only transcendental, but it is transcendent, for it does not have experience as its content. It is its own content. It is independent of all experience in three ways: (1) In origin, it contains only a formal principle; (2) In content, it contains only a formal principle; (3) In validity, it is not concerned as to whether it is obeyed or not; it declares what ought to be, even if what ought to be is never done. The question always arises about Kant’s ethics, Of what service can such a remote and formal principle be? Morality takes place in the world of experience; and here is Kant’s principle of morality existing in the world of unconditioned reality. Of the usefulness of such a principle Kant’s explanation is not fully satisfactory. His ethics is fundamentally a rigorism, from which he is unable to escape. Duty and inclination are in antagonism. Only those acts of will are moral which are performed solely from the sense of duty. In themselves the natural inclinations are indifferent; when they oppose the moral will, they become bad; only when they are inspired by the moral will are they of ethical service. Moral action is therefore narrowed to that in which the imperative of duty is consciously paramount.

The Moral Postulates. Kant’s ethical theory points away from the phenomenal world rather than toward it. To be sure, the natural inclinations take the color of the moral law when they are inspired by it; but the moral law tells us of the world of reality rather than of the world of phenomena. The moral law shows to man that he is more a resident of the world of reality than of that of phenomena. Man’s nature is dual. Of its two sides—the theoretical and the moral—the moral is primary. Fundamentally man is a willing agent rather than a thinking being. He is a phenomenal being, bound to the laws of natural necessity; but he is also a real unconditioned being, because the unconditioned reason is his real self. What was implicated in the Critique of Pure Reason becomes explicit in the Critique of Practical Reason. The understanding hints at what the will makes plain. Human knowledge is a mixture of transcendental understanding and empirical sensations. God’s knowledge would be pure understanding; the knowledge of the brutes is pure sensations. Human morality, however, contains a dualism; for the practical morality of man consists of the formal moral law inspiring the sensibilities although not heeding them. The will as pure reason is the activity of God; the will as pure impulses is the activity of brutes. But the true realm of man is this world of reason in which he is one with God, although he is at the same time hampered by being part of the world of phenomena.

1. The Postulate of Freedom. The unconditioned moral law is the basis of freedom for which all scientific knowledge seeks in vain. An unconditioned will is a free will. The will based upon the reason is based upon itself and is therefore free. The consciousness of the moral law within us implies freedom in its exercise. The “I ought” implies “I can.” We can have no knowledge of freedom, for in the eye of the understanding only causal necessity rules. But the reason commands as well as knows. It states what ought to be as well as what is. Its mandate implies freedom, as its knowledge states existence. When we will, we act as if we were free, and our freedom is a postulate which cannot be proved to the understanding. Freedom is not an object of knowledge, but an act of faith. Freedom as a postulate is the condition of morality, and the primacy of the will over the pure reason is shown in the fact that it can guarantee what the understanding cannot prove.

2. The Postulate of the Immortality of the Soul. The goal of the inclinations is happiness. The goal of the will is virtue. There is no relation or correspondence between the two in this world. A man may be happy and still not virtuous; he may be virtuous and not happy. Since a man belongs to both the world of free spirits and the world of necessity, he is thwarted in reaching for his highest good in this life. His highest good is the union of virtue and happiness. If this is to be attained, another life must be guaranteed. Yet this is only a postulate and not a proof. When man wills, he wills as if he were an immortal being.

3. The Postulate of the Existence of God. Faith in reaching forward must postulate God, as alone able to vouchsafe future harmony between goodness and happiness and alone able to distribute justly the rewards and punishments that are so disproportionate in this world. When I will, I will as if God existed. When I will, I create by my willing my freedom, my immortality, and God’s existence. But because my will is an unconditioned law of my real being, my faith in these things is well founded.58