Kant, Immanuel, designated by De Maistre" the philosopher of nebulous memory," acquired enduring renown as the author of the Critical Philosophy, as the father of the recent German or transcendental speculation, and as the most acute and profound metaphysician of the closing 18th century. The importance of his philosophical career is evinced by his furnishing the link of connection between the schools of Leibnitz, Locke, Berkeley, and Hume, and those of Hegel, Schellilg, and Comte. He closes one great and brilliant era of metaphysical inquiry; he commences another with singular fulness of knowledge, breadth of comprehension, perspicacity of discernment, and logical subtlety and precision. He exposed inveterate errors of procedure; he improved, sharpened, and refined the methods of investigation; he surveyed and plotted out the boundaries of metaphysical research; and he rendered more distinct and precise the nature of the inquiry, the subject with which it is concerned, and the instruments at our command for its investigation. These are inestimable services, the benefits of which are experienced even in the midst of the errors that have sprung from the system by which they were rendered.
Life. — Kant was born at Konigsberg April 22, 1724, and spent his whole life there or in its immediate neighborhood, never having journeyed more than forty miles from his native place. He ended his tranquil life in the city of his birth, February 12, 1804. He was of Scotch origin. His father, John George Cant, removed from Tilsit, where his immigrant grandfather first settled, to Konigsberg, and followed the saddler's trade with little worldly success. His pinched fortunes were ennobled by stern and unostentatious integrity. All accounts commemorate the high character, intelligence, and austere piety of Anna Regina Reuter, the philosopher's mother-virtues affectionately attested by her illustrious son, who ascribes all that was best in himself to her example and instructions, and to the purifying influences of his childhood's home. He lost his mother when he was eleven years of age, his father in his twenty-second year (1746). They lived long enough to, transmit to him the memory of their virtuous example-'twas all they had to bequeath. After receiving the first rudiments of education at the charitable schools of the city, he was sent to the Frederick College in 1734, at the expense of his uncle, a substantial shoemaker. Here he remained for seven years under the care of Dr. Schultz, an eminent adherent of Wolf, at the time when the Wolfian philosophy was a subject of acrimonious controversy. He devoted himself chiefly to the classics and mathematics, the essential foundation of all thorough instruction, and had Ruhnken for his fellow-student. From the Collegium Fredericianum he passed in 1740 to the University of Konigsberg, and entered upon a course of theology; but his ill success in preaching discouraged him, and he attached himself to the mathematical and physical sciences, in the former' of which his first distinction was gained. During the latter period of his university career he supported himself by teaching in the humblest grades, in consequence of the increasing penury of his father, whose death in 1746 compelled him to withdraw from the university, and to seek a living from his own exertions alone. For the nine following years he was employed as a private teacher in or near Konigsberg, and finally in the noble family of Kayserling, by whom his merits were appreciated, and in whose society he acquired that polish of manner which distinguished him through life. He changed his family name of Cant to the more Germanic appellative Kant, but he did not thus divest himself of the Scotch characteristics of mind and morals. In the second year of his engagement in private tuition he published his first work, Gedanken von der wahren Schatzung der lebendigen Kriafte (Thoughts on the true Measure of Living Forces, 1747), which was esteemed a valuable contribution to the famous controversy on the subject. In 1754 he discussed the question proposed for a prize by the Berlin Academy, Whether the Earth had undergone any change consequent upon its revolution upon its Axis. This essay facilitated his acquisition of the master's degree, in the next year. At this time he returned to the university as privat-docent, and maintained an uninterrupted connection with it thenceforth till the closing years of his life. He inaugurated his lectures by the composition of two theses: the first, De Igni; the second, Dissertatio de Principiis Primis Cognitionis Ilumance, which was the first manifestation of the direction of his mind to metaphysical inquiry, and also showed that he had fixed on the central point of all philosophy. While employed in private teaching he had diligently prosecuted his encyclopaedical studies, and had acquired the English language by his own exertions, in order to master the speculations of Locke, Berkeley, and Hume. Another kindred treatise belongs to this year-Principioru m Primorum Cognitionis Metaphysicae Nova Dilucidatio, as also his Allgenzeine Naturgeschichte und Theorie des Himmels (Universal Natural History and Theory of the Heavens). The last work was issued anonymously, with a dedication to Frederick the Great. It is remarkable for its bold views, and for announcing the probable resolution of the nebulae into'stars, and the probable discovery of new planets-scientific predictions fulfilled in much later years by Herschel and Leverrier. This production occasioned a correspondence with Lambert (1761), the singularly profound president of the Berlin Academy, who espoused similar opinions. For fifteen years (17551770) Kant lectured to private classes in the university. His courses treated "peene de omni scibili,"but were marked by a special addition to the physical sciences, and, after 1757, to physical geography, a novel branch of knowledge which he continued to expound annually till the close of his academical career. A life so retired as Kant's, and so exclusively occupied with study and the duties of instruction, scarcely offers any events for biography beyond the development of opinions, the publication of the treatises in which such opinions are set forth, and the academic distinctions attained. The chronicler finds little to report more exciting than Dr. Primrose's migrations "from the blue chamber to the brown," and hence is compelled to mark the critical moments of his career by the notice of the principal works as they appeared. Such indications, however, have a value of their own, as they reveal the growth of speculations which have moulded the intelligence of the world, and mark the times and modes in which the revolutions of thought have been effected. In 1762 appeared Kant's criticism of the Aristotelian logic, in a treatise entitled Diefalsche Spitzfindigkeit der vier syllogistischen Figuren (False Subtlety of the Syllogistic Figures).
The censors of Aristotle have usually misapprehended Both his doctrines and his aims, and have imagined to be erroneous dogmas which the Stagyrite had meditated more profoundly, and had treated with a juster regard to practical convenience than themselves. In the course of the next year, 1763, Kant gave to the public his Der einzig mogliche Beiweissgrund zu einer Demonstration des Daseyns Gottes (Ontological Demonstration of the Being of God), in which he repudiated alike the deductions a priori of Anselm, Des Cartes, and Clarke, and the inductions a posteriori of the natural theologians, and regarded the conception of the possibility of God as attesting the reality of his existence. This treatise still bears the impress of the dominant Wolfian philosophy, which he had imbibed from his early teacher Schultz. In this year he contended for the prize offered by the Berlin Academy, his treatise on the Principles of Natural Theology and Morals (Untersuchung uber die Deutlichkeit der Grundsatze der naturlichen Theologie und Moral) receiving the second honors, while the first were adjudged to Moses Mendelssohn. Three years more elapsed before he received his first public appointment as underkeeper of the Royal Library, with the scant salary of fifty dollars., In this year he exposed the pretensions of Swedenborgianism, being always ready to assail new- fangled delusions, whether stimulated by enthusiasm or by imposture. At length, when approaching the end of his forty-seventh year, he was promoted to the chair of logic and metaphysics in his own university, with a stipend of three hundred dollars. He had suffered two previous disappointments. He had failed to obtain the professorship extraordinary of logic in 1756, and the ordinary professorship in 1758, and had declined the professorship of poetry in 1764, from distrust of his aptitudes and acquirements. He had refused invitations from Erlangen and Jena, from reluctance to abandon his people and his native home.
Custom demanded an inaugural dissertation from the professor elect. Kant's subject was De Mundi Sensibilis atque Intelligibilis Forma et Principiis. This essay contained the first distinct anticipations of his characteristic system, though his philosophy did not receive form or coherent development for many ensuing years. The remainder of his life was, however, consecrated to its definite constitution and exposition. It early began to assume shape, for in 1772 he smoothed the way for a fuller discussion by his Scheme of Transcendental Philosophy. No desire of change, no temptation of worldly advancement and honor could seduce him from-his calm lucubrations. He refused to go to Halle, though a double salary was offered him. After eleven years of patient meditation he produced in 1781 his Critique of the Pure Reason (Kritik der- reinen Vernunft), which proclaimed a new philosophy, and ushered in a new cycle of speculation-novus ordo sceclorum metaphysicorum. The work was modified in a second edition in 1787, to obviate the imputation of idealism and idealistic infidelity objected to it as to the previous system of Wolf. It long seemed as if this remarkable production-a revolution itself, and the parent of revolutions-would never reach a second edition. For six years it lay so unheeded on the publisher's shelves that he contemplated disposing of it as waste paper, when a sudden demand relieved his anxieties, and rendered a republication expedient. This timely interest in the book was scarcely due to Kant's Prolegomena to Metaphysics (Prolegomena zu einer jeden kunfigen Metaphysik, die als Wissenschaft wird auftreten konnen, 1783), but may be attributed to striking notices of the doctrine in prominent German magazines. In 1785 the practical side of his system 'was exposed in his Metaphysics of Ethics (Grundlegung zur Metaphysik der Sitten), and in the following year its extension to physical speculation was attempted in his Metaphysics of Natural Science (Metaphysische Aufangsgriinde der Naturwissenschaft). In 1788 the positive aspect of his philosophy was presented in the Critique of the Practical Reason (Kritik der praktischen Vernunft), which treats of the principles and objects of the moral law, and constructs ethics on the formula, Act so that your principle of action may serve as a universal law. The foundation is narrow, and has the cold rigidity of Stoical pretension, but it was a stern and strict rule in the conception of its propounder, and was borrowed from his own line of conduct, and from the austere virtues of his parental home, as much as from the dictates of his reason. The defects of this canon will be indicated hereafter. The outline of the new philosophy was completed in 1790 by the Critique of the Practical Judgment (Kritik der Urtheilskraft), which is in some respects the most satisfactory work of the series. It is designed to unite the practical with the theoretical reason, the freedom of the will with the law of existence, by regarding the whole order of creation as a system of means effectually adapted to the attainment of beneficent aims. It is thus a tractate of teleology or of final causes. It is principally occupied with the theory of the beautiful and the sublime, and is in great measure a development of the Observations on the Beautiful and the Sublime. (Beobabhtungen uber das Gefiihl des Schonen und Erhabenen, 1764), and the Metaphysics of Ethics (1785).
Kant's metaphysics had thus been exhibited by himself in all its principal applications. It had attracted general notice; it had gathered around it numerous and enthusiastic disciples; it had secured for its author profound respect and earnest admiration. Distinguished men flocked to his lectures; princes and sovereigns commissioned learned scholars to hear his teachings and to report his doctrines. His life was surrounded with ease, and his days were crowned with honor. His salary had been increased, and had given what was wealth to one of his simple tastes and frugal habits. He had been twice appointed rector of the university. His industrious and meditative career had passed its grand climacteric, and was stretching serenely to its close. Just when the aims of life appeared to have been won, Kant was plunged into the only serious troubles which disturbed his tranquil existence. He became involved in a grave religious controversy by some articles in a Berlin magazine, afterwards reproduced in a volume under the title of Religion within the Limits of Pure Reason (Die Religion inner halb der Grenzen der blossen Vernunft, 1793). There was a ferment in the religious circles of Germany at this time, and Kant's philosophy had early excited alarms which appeared now to be justified. A doctrine which rejected the accepted arguments for the being of God, the validity of revelation, the immortality of the soul, and the creation of the world, offended too many convictions, unsettled too many inveterate habits of thought, and substituted too shadowy and too abstract speculations for accredited precepts and dogmas, not to produce discontent and censure. Nor were the alarms entertained unreasonable, as was shown by the subsequent developments of the transcendental philosophy. The agitation excited by Kant's theological innovations was partially allayed by a royal mandate directing him to observe silence on religious topics. The king's interference is supposed to have been induced by Kant's sympathies with the French Revolution, despite of the Reign of Terror. On the death of the king in 1797 he resumed-his expositions, considering his engagement as a personal one with that monarch. But before this time he had narrowed the sphere of his activity. In 1794 he withdrew from general society; in 1795 he discontinued all his instructions except in logic and metaphysics, and he closed his academic labors altogether two years afterwards. In 1798 he composed his Strife of the Faculties (Der Streit der Facultaten), reviving the religious dispute in which he had been entangled; and he bade farewell to the public in his Pragmatical View of Anthropology (Anthropologie in pragmatischer Hinsicht). The last work from his own pen was a protest against Fichte's doctrine, which gave to the new philosophy the. subjective or idealistic cast, against which his own efforts had always been strenuously directed. In this paper were manifested his own failing powers, and his incapacity to appreciate other systems than his own -a natural consequence of his habitual disregard of the history of speculation. His pupils published several other works from his notes and papers during the last years of his life. That life was not long extended after his retirement. His constitution gradually broke up; his health, so remarkably maintained, began to decline; appetite, teeth, strength, sight, voice, memory, all failed, and his pure, laborious, and honorable existence was terminated by an apoplectic attack, Feb. 12,1804, when he had nearly completed his eightieth year. His death produced profound emotion throughout Germany. The whole city of Konigsberg put on mourning; multitudes flocked to his funeral, and his remains were escorted to the grave by a solemn procession. A characteristic medal was struck to commemorate his fame. It bore an emblem and a motto appropriate to his doctrine, "Altius volantem cbercuit." He was worthy of such honor. He left to his countrymen the example of a career rich in wholesome fruits- simple, sincere, upright, laborious; devoted singly to the promotion of truth, and to the removal of error in the highest and most perilous regions of speculation, illustrated by seventy years of unbroken industry, and by half a century faithfully given to the instruction of successive generations of the young in various branches of learning, from the humblest rudiments of knowledge to the most recondite metaphysical research. Humble, modest, and true, his life was a nobler crown to his memory than all the honors that men could bestow.
In person, Kant was small and delicately built. His blue eyes expressed benevolence, but his features were rugged, and seamed with the lines of habitual thought. Lavater mistook his portrait for that of a noted highwayman. His manners were kindly and courteous. He was very genial in company, full of mirth and innocent wit, and scrupulously abstinent of learned or metaphysical discourse. As a lecturer he was easy and attractive, displaying nothing of the repulsive aridity and elaborate awkwardness of his philosophical treatises. He was a reverential observer of all truth, and rigid in the practice of all justice. The like precise propriety regulated all his habits. He was plain in his tastes, abstemious in eating and drinking, chary of indulgences, frugal in his expenditures, methodical in every arrangement. "Early to bed and early to rise" was the rule of his life. His hour for rising was four in summer and five in winter; for bed, ten in summer and nine in winter. By this regularity and moderation he reached fulness of years with health, cheerfulness, and perfect serenity. He seems to have been deficient in poetic sensibility and poetic imagination. To this defect may be ascribed several imperfections in the exposition of his philosophy, and his total want of religious sentiment. Shortly before his death he declared that he had no determinate notion of a future state, but was inclined to believe in metempsychosis. This was the flaw in his mental and moral constitution which produced many flaws in his speculation.
Like his illustrious contemporary Hume, whom he survived nearly thirty years, Kant was never married. He gave no "hostages to fortune," but illustrated Bacon's dictum, that " the best works, and of greatest merit for the public, have proceeded from unmarried or childless men." Of the works constituting Kant's bequest to posterity, the most noted and important are those that expound the "Critical Philosophy," and of this philosophy a brief notice remains to be given.
Philosophy. — Kant's scheme of speculation is so comprehensive, so extensive, so intricate, so systematic, so full of divisions and subdivisions, that it is impossible to attempt any complete summary of it within the limits allowed by this article. Not the fullest, but the most compact mode of exposition is required.. Hence the notice of the numerous treatises not directly employed in the construction of the "Critical Philosophy" has been introduced into the biographical sketch. Hence, too, the reader who desires a formal outline of the system must be referred to some of the numerous synoptical views presented in German, French, English, and Latin. All that can be aimed at here will be to give a cursory account of the distinctive peculiarities of Kant's scheme. To do this, it may suffice to explain his relation to previous philosophy, to point out his characteristic method, and to note the chief developments and applications of that method.
To show the exact relation of Kant to antecedent and contemporary modes of speculation would require a detailed account of the fortunes of philosophy from Bacon, and Gassendi, and Des Cartes. This is more than has been attempted by Rosenkranz. It must suffice to state that in the middle of the 18th century the Wolfian development and systematization of the philosophy of Leibnitz was predominant in Germany; the scepticism of Hume perplexed and alarmed Britain; and the materialism of D'Alembert, Diderot, and Condillac was fashionable in France. The philosophy of Leibnitz was an effort to escape the pantheistic tendencies of Cartesianism as evolved in the idealism of Spinoza and the theosophism of Malebranche. Hume's philosophy was the sceptical evolution of the sensationalism of Locke, generated by the collision between the mechanicism of Hartley and the Pyrrhonism of Berkeley. The infidel doctrine of the school of the French Encyclopsedia was the superficial deduction of the French intellectual anarchists from the partial appreciation of the tenets of Locke, whose own principles were vague and incoherent. The problem presented for solution was to find some ground of conciliation between all these divergent opinions, to detect and expose the fallacies on which they rested, to avoid the mischiefs caused or portended by them, and to discover a trustworthy and intelligible basis for human knowledge. The situation was in many respects analogous to that which characterized the Hellenic world at the time of Socrates. Kant undertook the investigation of this arduous and urgent problem, and, like Socrates, he proceeded by the critical investigation of the nature of knowledge and of the intellectual faculties of man. By this procedure he was gradually led to the determination of the conditions of the problem, and to the discovery of a solution partially true, and which appeared to himself complete and irrefragable. In metaphysics the method is the philosophy, and Kant's method gave to his system the appropriate name of the Critical Philosophy.
It must be remembered that Kant's early guide was Schultz, an earnest partisan of Wolf; that Kant proceeds from, the Wolfian, that is, from the methodical Leibnitzian School; 'that he slowly emerges from the Wolfian circle, and that Wolfian characteristics may be traced throughout the whole construction of his scheme.
The response made by Leibnitz to the th(sis of Locke -" Nihil est in intellectu quod non prius in sensu"-a dogma by no means Aristotle's, and only virtually Locke's -furnishes the key-note to the whole philosophy of Kant. "Nisi intellectus ipse," replied Leibnitz; thus distinguishing the faculty of thought from the impressions it receives, and offering a refutation at once of both the sceptical and the materialistic followers of Locke. The same just discernment may be found in Aristotle, though it has been little noticed (Analyt. Post. ii, xix). What was required was the discovery of some principle of intelligence, some interpretation of the process of human thought, which would withdraw the mind of man from the arbitrary government of a Providential compulsion, a blind necessity, or a mechanical regulation by material constitution or by external chance. Kant sought this principle in the constitution and limitations of the human mind. He analyzed the products and the processes of thought. He found that in every perception, in every judgment, in every generalization, the mind communicated, something of its own to what was presented as the object of knowledge; that in every apprehension, what was apprehended was moulded and determined by the intelligence which apprehended it. To use the language of the school, the form of knowledge was necessarily imposed by the constitution of the cognizant mind. This seems to have been the doctrine of Aristotle (τὴν ψυχὴν εῖναι τόπον εἰδών, De Anim. 3:iv), and was deduced from his teachings by his scholiast, Asclepius.
It was slowly that Kant reached this conclusion, which became very prolific in his hands. He tells us that it was due to the examination of Hume's denial of any nexus between cause and effect, which of course reduced the universe to a disconnected dream, and rendered all knowledge the mere aggregate of impressions fortuitously succeeding each other. He found that the same difficulty which -had been exposed by Hume in regard to cause and effect existed in the case of all synthetic judgments a priori, or those which unite two unconnected conceptions in one proposition. Truth was thus deprived of all validity, and experience became fallacy. How could a firm foundation be attained'? Was experience as hollow, and spectral, and delusive as it had been represented by Hume? Three questions presented themselves for solution, each corresponding to a distinct branch of metaphysical inquiry: " What an I know?" "What ought I to do ?" "What may I hope for?" The answer to the first question; which was the investigation of the nature of knowledge and of the nature of the mind, was given in the Critique of the Pure Reason. The answer to the second, which embraced the theory of duty, was propounded in the Critique of the Practical Reason. The answer to the third, which contemplated the summum bonum under a peculiar aspect, was presented in the Critique of the Judgment-a very ambiguous designation. This distinction of subjects and division of treatises sprung from the distribution of the matter of philosophy then prevalent in Germany. The distribution had itself descended from Aristotle (θεωρητικὴ γὰρ καὶ πρακτικὴ καὶ ποιητικὴ λέγεται scil. ἐπιστήμη. — Top. 6:6; comp. Metaph. 5:1; 11:7; 12:9).
(1) The Critique of the Pure Reason contains the essence of Kant's philosophy. It exhibits his method, illustrates his procedure, and presents his fundamental conclusions; The conception of the Pure Reason is in great measure his own, though both the name and what is denoted by the name are found in previous systems (Plotinus, Ennead. 5:3, 3; Leibnitz, Theod. § 1; Nouv. Ess. ii, 4:§ 3). The pure reason is reason in its essential constitution — ἐν δυνάμει, not ἐν ἐνεργείᾷ –the thinking faculty in its adaptation to thought-empty of the matter of thought, and distinct from its experiences. It is the mill without the grain which is to be ground by it. In analyzing the principle of thought, Kant detects an active as well' as a passive factor. In every act of thought there is the reception of the impression from the object of thought, and the subjective reaction thereby excited, which reaction communicates the rational form to the conclusum, and differentiates τὸ νούμενον, the subject of thought, from τὸ φαινόμενον, the object of thought.
Kant distinguishes the agencies which supply the materials of knowledge into three-sense, understanding, reason. The distribution of the faculties of the mind is always hazardous, and often beguiling. The mind is one and complete. In the perceptions of sensation, the elements derived from the mind, and not from the impression, are space and time. Such elements are called transcendental because they transcend, precede, and formulate the experience. They are consequently the forms or conditions of sensations. They are not supplied by the sensation, but they are added to it by the mind in the act of perception. There are indications of this doctrine in Plotinus (Ennead. ii, 7,9), Leibnitz (Nouv. Ess. liv. ii, chap. v), and il other writers. It is intimated, indeed, by Aristotle, and is a natural deduction from the Ideas of Plato. It is singularly corroborated by recent expositions of the physiology of nervous action. In Kant's theory the phenomena of the external world are all subject to the conception of space, the phenomena of the mind to the conception of time. The sensationalist is thus refuted, as space and time are not obtained from sensation. The dogmatic idealist is refuted, as the matter of knowledge must be supplied by external impressions.
The understanding co-ordinates the perceptions of sense, and forms them into judgments by giving to them unity and interdependence. The transcendental elements supplied in this action of the understanding are arranged by Kant in twelve categories. The name of categories is taken from the Organon of Aristotle, but Kant's categories are entirely diverse from Aristotle's. Kant observed that metaphysical science pursued a delusive round, without making progress or securing stability, while logic had received full, complete, and definite form from its great founder. He ascribed this difference of fortune to the fact that logic was simply the exposition of the procedure of the mind in reasoning, and he concluded that equal validity would be conferred on metaphysics, if it were reduced to an accurate representation of the procedure of the mind in the acquisition and employment of the materials of knowledge. Hence he invented a forced analogy between the two branches of speculation, and rendered his theory intricate, arbitrary, and obscure' by compelling it to assume a form fantastically corresponding with logical distinctions. In this spirit he devised his twelve categories, and arranged them according to the forms of propositions, in the manner exhibited in the following table:
Logical Transcendental I. Quantity Universal, Particular, Singular II. Quality Affirmative, Negative, Indeterminate III. Relation Categorical, Hypothetical, Disjunctive IV. Modality Problematical, Assertory, Apodeictic Unity, Plurality, Totality Reality, Negation, Limitation Substance, Cause, Reciprocity Possibility, Existence, Necessity
All judgments are framed by the mind under the influence of these categories, four of them-one from each class-being inevitably applied. in every instance. As, however, things are thus seen, not as they are, but as the intellectual predispositions make them appear to be knowledge is purely relative to the human mind-objective truth is not attainable, and all our experiences or knowledge have only a subjective validity. The mind cannot think except so far as it has been provoked by objective stimulation, therefore there is a real objective existence of things. It thinks under the control of the categories of the understanding, therefore knowledge is subjective in form, is moulded by the recipient mind, and cannot be known to correspond to the reality of things. The image is reflected from the mirror, but the object represented may be magnified or diminished, or strangely distorted by the character of the mirror, without being altered in itself. The image is all that constitutes-knowledge; there is, accordingly, no. assurance of agreement between the image and the object. Thus all knowledge is conditional only-conditioned by the forms of the understanding, which mould it into the form in which it is received. Some principle was required to give coherence, unity, confidence to the relative knowledge obtained through such mental experiences. This was supposed to be given by the consciousness of personality which bounded, adunated, and harmonized all the qualified judgments that could be entertained.' It seems a misapprehension on the part of Kant, and at variance with his system, to claim any necessary truth for judgments formed in this manner. There can be nothing more than a relative or contingent necessity-an impossibility of thinking otherwise than the constitution of the mind necessitates.
In the highest region of the mind-the reason or the faculty of ideas — there is also subjection of the matter of knowledge to transcendental forms. But the functions of the reason pass beyond the limits of experience, and are only regulative. In this branch of the subject, which is designed to explain the combination of the judgments of the understanding into ratiocinative. conclusions, Kant introduces three pure ideas, which are deemed to be analogous to the three forms of the syllogism-categorical, hypothetical, and disjunctive. These ideas are,
1. Absolute unity, or simple being, the soul, which gives origin to Rational Psychology;
2. Absolute totality, the aggregate of phenomena in space and time, the world, which is the basis of Cosmology; and,
3. Absolute reality, supreme existence, the First Cause, which is the subject of Theology. From this point the later German schools diverge by ascribing a real and not simply a subjective validity to the forms of the absolute. With Kant they are merely postulates of reason, having no assured objective existence. Rational psychology only exhibits the phenomena of mental consciousness without guaranteeing anything in regard to the essential nature of the mind or to the immortality of the soul. Rational cosmology is equally unable to attain to any positive knowledge in regard to the creation. It lands us finally in four pairs of transcendental ideas, each pair producing twin contradictions.
These are Kant's celebrated antinonies:
1. In quantity, it may be proved that the world is both limited and unlimited;
2. In quality, that its elements are ultimately simple and infinitely divisible;
3. In relation, that it is caused by free action, and by an infinite series of mechanical causes;
4. In modality, that it has an independent cause, and that it is composed of interdependent members. Whichever of these alternatives be asserted, it cannot be exclusively maintained, for it results in hopeless paralogisms. Both must be in some sense true, yet both cannot be simultaneously entertained, because they are contradictory. Hence no certainty, no complete comprehensive knowledge can be attained. Metaphysics is simply inquisitive, speculative, critical, showing the limitations of the human mind, and the impossibility of knowing the reality of things, but at the same time furnishing glimpses of a reality which the mind can not compass-of existence and truth beyond the range of finite comprehension. It is the confession, if not the demonstration of the intellectual weakness of man. The same negative result is reached in rational theology. The ontological argument for the being of God-that of Anselm and Des Cartes, derived from the notion of perfect and independent existence-the cosmological argument of Clarke, which proceeds from the conception of contingent to that of necessary being-and the physicoteleological argument of the natural theologians, which infers a supreme intelligent Designer from the evidences of design in the creation, are all equally inconclusive. "Thus the soul, the world, and God are left by Kant's speculative philosophy as problems not only unsolved, but demonstrably unsolvable." To furnish a positive support for convictions on this subject indispensable for human guidance, and to give an authoritative rule for action, Kant constructed his ethical systems.
(2) Critique of the Practical Reason. — Neither the name nor the conception of the practical reason was a novelty; both occur in Aristotle (De Anim. 3:10; ὸ μὲν γὰρ θεωρητικὸς νοῦς οὐθὲν νοεῖ πρακτόν, ibid. c. ix). They are found in Aquinas (Summn. Theol. ii, 1, 90, and especially 91,3), in Roger Bacon (Opus Majus, p. 35, 44), and in most philosophers, medieval and modern, who have accepted the Aristotelian doctrine. Whatever, systems have recognised a moral sense, whatever theories have admitted a sustaining and guiding illumination of the conscience, whatever schemes acknowledge the inworking spirit, and whatever expositions of the mysteries of man assume an abiding faith as the foundation of moral action, entertain substantially the same fundamental doctrine as Kant's, though it is differently expanded and applied by them. The characteristic feature of Kant's ethical system is what he terms the " Categorical Imperative." Speculative philosophy affords neither absolute truth nor certain guidance. Practical philosophy rests upon the enlightened conscience-enlightened by its own indwelling light. The "categorical imperative" is a rule of action-a moral law deriving its authority from itself-intuitively received determining action by the idea- governing by the rational form, not by the matter-thus advancing to the realm of the absolute, the unconditional, the noumenal, and passing from the shadows of speculation to the realities of action and duty. The formula of this." categorical imperative" is, Act so that your action may be applied as a universal rule. It is obvious that a precept so vague and so abstract may represent an essential characteristic or property of right conduct, but cannot be accepted as its principle. It is indefinite, and it wants the authority of sovereign command. It would require the omniscient comprehension of all contemporaneous relations, and all possible consequences for the regulation of every act, and at best would result in transcendental utilitarianism. It is too abstruse to be promptly and habitually applied to all the occurrences of life, and by all grades of men. It is limited to finite intelligences, and is sufficiently elastic to allow each one's ignorance or obtuse conscience to be alleged as the individual rule of right. It might easily be stretched so as to sanction the Donatist thesis, " Quicquid libet, licet." On such a scheme, to employ the expression of Lyly's Euphues, "it is the disposition of the mind that altereth the nature of the thing." Our morals would be shifting and casuistical. The wish would continually be the father to the thought; and all enthusiasm, all fanaticism, all monomania might be presented as the canon of order. The conception of duty is the touchstone and stumbling-block of philosophy, and against it is shattered every scheme which does not rest upon the acceptance of revelation, and the acknowledgment of God, in whom we live, and move, and have our being." There is no other mode of passing the chasm which separates the negative results of speculative inquiry from the positive requirements of practical action. Speculative philosophy discusses the boundaries of the mind; practical philosophy is concerned with actions which are infinite in their consequences, and whose effects " wander through eternity."
(3) The Critique of the Judgment (Urtheilskraft — Faculty of Judgment).- This is the third of the systematic treatises devoted to the construction of the critical philosophy. The designation is infelicitous and. ambiguous. The Imagination would be more appropriate, but would scarcely be applicable without some violence to the whole scope of the inquiry proposed. The department corresponds to the ἐπιστήμη ποιητική, or constructive science of the peripatetic distribution of knowledge and connects the domain of the pure with that of the practical reason. The imagination is the faculty of conciliation-of recreation-uniting in emotional delight the obligations of action with the highest discoveries of speculation. In Kant's critique of the judgment are included the doctrine of the beautiful and the sublime, or esthetics, and the doctrine of final causes, or teleology. His theory of beauty accords in substance with that of Plato, or rather that of Plotinus, but from his own singular defect of imagination, and consequent limitation of view, it is denied the completeness, splendor, and fulness of far-reaching suggestion which illustrate that magnificent exposition of the grandest and most recondite subject of metaphysical speculation. In beauty. Kant contemplates only the latent beneficent design, the harmony of means and ends, without dwelling upon the more significant conception of the primordial plan, the archetypal perfection, from which the whole creation has declined, but towards which man's ideal ever strives to return. The terms in which the doctrine is expounded are often confused and indistinct, but the essential principle of beauty, which is not in things, but in the mind, is the intuitive perception of the concord between the ideal perfection suggested and the order of the universe observed. The principle of the sublime is the intuition of the discrepance between the finite powers of man and the infinite towards which he aspires, producing pain from the sense of limitation, but exaltation from yearning towards the limitless, beyond sense and conception, which is felt to be his natural home, his ultimate destination. In the discussion of teleology proper Kant en' deavors to restore some efficacy to that reasoning from final causes which in earlier treatises he had repudiated. This part of the subject is inadequately unfolded, but it presents many vast and suggestive views, and in some sort prepares the way for the last of Kant's treatises which can be specially noticed here.
(4) Religion within the Limits of Pure Reason. — This is Kant's theology, and is the most unsatisfactory of all his efforts. It was an attempt to reconstruct the foundations of religious belief, which had been sapped and in great measure overthrown by his critical investigations. It was the work of his old age, and at all periods of his life he seems to have been at least as deficient in religious sentiment as in emotional imagination, which is closely allied to it. The work provoked much opposition at the time of its appearance, and caused the only serious annoyance of his life. It scandalized many religious minds, it was dangerously consonant with the revolutionary infidelity of France, and it presented the point of departure for the German rationalism of the 19th century. It treats the revelations of Scripture in regard to the fall of man, to his redemption, and to his restoration as a moral allegory, the data for which are supplied by the consciousness of depravity, and of dereliction from the strict principles of duty.. It is Strauss in the germ. It is utterly inconsistent with any scheme of religion, and serves to show Kant's profound sense of the insufficiency of his own doctrine for the solution of the highest enigmas of humanity. The wroi ποῦ στῶ-the solid locus standi was wanting to his elaborate system. The philosophy was wholly critical in its procedure, and negative in its results. It weakened or undermined those intuitive convictions-inexplicable, but irrefragable-which enable man "to walk by faith, and not by sight." This notice is too brief to allow the exhibition of the incongruities or fallacies of the transcendental system, or the suggestion of rectifications, as it has been too brief for any detailed account of the several parts of his complex and elaborate scheme: That scheme is a wonderful monument of patient industry, acute discernment, perspicacious analysis, and of bold and honest thought. It was soon felt to be unsatisfactory, and it engendered new swarms of speculative heresies; but its influences must be sought in Rosenkranz's history of Kant's doctrine, and in other treatises on the history of German speculation.
Literature.-The bibliography of Kant's philosophy would make the catalogue of an extensive library, and would include nearly everything in the highest branches of metaphysics which has appeared since the publication of the Critique of Pure Reason. In all the general histories of modern speculation, much space is of course conceded to this subject. The following treatises may be examined with advantage. Kant, Werke, of course. The best editions are that of Hartenstein (Leipzig, 1838-9,10 vols.), and that of Rozenkranz and Schubert (Leipzig, 1840-42, 11 vols.), including a full biography of the philosopher by Schubert, and an elaborate .appreciation of the relations and influences of the philosophy by Rosenkranz. It gives also a chronological catalogue of Kant's multifarious writings. Recent translations into English are those of his Critik of Pure Reason, by Hayward (Lond. 1848, 8vo), and by Meiklejohn (Lond. 1856, 8vo); of his Metaphysics of Ethics, by Semple (Lond. 1856, 8vo); of his Theory of Religion, by the same (Lond. 1858, 8vo). There are biographies by Borowsky (1804 : this was revised by Kant); by Wasiansky, his private secretary, giving an account of his last years (1804); by Jachmann (1804); by Hasse (1804); and the ablest by Kunotischen of Jena (1860). For the appreciation of the doctrine the following works may be consulted: Nitzsch, General and Introductory View (Lond. 1796); Schmidt-Phiseldek, Expositio Philosoph. Crit. (Hafn. 1796); Mellin, Encyclop. Dict. of the Kantian Philosophy (1797, 6 vols.); Willich, Elements of the Critical Philosophy (London, 1798); Villers, Philosophie de Kant (Metz, 1801); Degerando, Hist. Comp. de Philosophie (Paris, 1804); Wirgman, Principles of the Kantesian Philosophy (London, 1824-a recomposition of an able article contributed to the Encyclopaedia Londinensis in 1812); Cousin, Legons sur la Philosophie de Kant (Paris, 1842; translated by A. G. Henderson, Lond. 1871, 8vo); Murdoch, Sketches of Modern Philosophy (1842); Barchou de Penhon, Hist. de la Phil. Allemande depuis Leibnitz jusqu'a Higel (Paris, 1837, 2 vols.); Erdmann, Gesch. der neueren Philosophie; Michelet, Geschichte des letzten Systems; Willm, Histoire de la Philosophie Allemande (Paris, 1847, 4 vols.); Morell, Philosophy of the 19th Century (1848); Chalybseus, Histor. Entwickelung d. spekulativen Philosophie von Kant his Hegel (4th edit. Leipz. 1848); E. Remhold, Gesch. d. Philos. (4th ed. Jena, 1854), vol. iii; Lewes, History Philos. (3d ed. 1871, 2 vols. 8vo), vol. ii; Hurst's Hagenbach, Church Hist. 18th and 19th Cent. (N. York, 1870, 2 vols. 8vo), lect. 4:sq.; Farrar, Crit. Hist. of Free Thought. Very instructive notices of Kant and his philosophy are contained in the North British Review, vol. 10:the Encyclopcedia Britannica, and in Appleton's American Cyclopcedia. The criticisms of Dugald Stewart in the Supplement to the Encyclop. Britannica are wholly unsatisfactory. (G. F. H.)