The critique of reason has to investigate what the
especial
Forms of this synthesis are in each stage, and in what their universal and necessary validity consists.
Windelband - History of Philosophy
, 1892]), has diligently collected the literature.
Separate editions of the Kritik, by K.
Kehrbach, upon the basis of the first edi tion, and by B.
Erdmann [and E.
Adickes] upon the basis of the second edition.
[Eng.
tr.
of the Critique (2d ed.
), by Meiklejohn, in the Bohn Library, and by Max Mliller (text of 1st ed.
with supplements giving changes of 2d ed.
), Lond.
1881 Paraphrase and Commentary by Mahaffy and Bernard, 2d ed.
, Lond.
and N.
Y.
1889 partial translations in J.
H.
Stirling's Text-book to Kant, and in Watson's Selections, Lond.
and N.
Y.
1888.
This last contains also ex tracts from the ethical writings and from the Critique of Judgment.
]
1876).
Cf. also
The additional main writings of Kant in his critical period are Prolegomena zu einer jeden kUnftigen Metaphysik, 1783 Grundlegung zur Metaphysik der Sitten, 1785 Metaphysische Anfangsgrunde der Naturwissenschafl, 1785 Kritik der praktischen Vernunft, 1788 Kritik der Vrtheilskraft, 1790 Die Religion innerhalb der Grenzen der blossen Vernunft, 1793 Zum ewigen Frie- den, 1796 Metaphysische Anfangsgriinde der Rechts- und Tugendlehre, 1797 Der Streit der FakultSten, 1798 [Eng. tr. of the Prolegomena, by Mahaffy and Bernard, Lond. and N. Y. 1889; of the Prolegomena and Metaphysical Founda tions of Natural Science, by Bax, Bohn Library of the ethical writings, includ ing the first part of the Religion within the Bounds of Pure Reason, by T. K Abbott, 4th ed. , Lond. 1889 of the Critique of Judgment, by J. H. Bernard, Lond. and N. Y. 1892; of the Philosophy of Law, by W. Hastie, Edin. 1887; Principles of Politics, including the essay on Perpetual Peace, by W. Hastie, Edin. 1891. The contents of Kant's Essays and Treatises, vols. , Lond. 1798,
F. W. Schubert (12 vols. , Leips. 1833 ff. ), G. Hanenstein (10 vols. , Leips. 1838 f. , and recently vols. , Leips. 1867 ff. ), and J. v. Kirchmann (in the Philos. Biblioth. ). 1 They contain, besides his smaller articles, etc. , his lectures upon logic, pedagogy, etc. , and his letters. A survey of all that has been written by Kant (including also the manuscript of the Transition from Meta physics to Physics, which without value for the interpretation of his critical system) found in Ueberweg- Heinze, III. 24 there, too, the voluminous literature cited with great completeness. Of this we can give here only a choice of the best and most instructive survey of the more, valuable literature, arranged according to its material, offered by the article Kant, by W. Windel band in Ersch und Gruber's Enc. [The Journal of Speculative Philosophy contains numerous articles upon Kant. We may mention also Adamson, The Philosophy of Kant, Edin. 1879; art. Kant, in Enc. Brit. , by the same author; arts, in Mind, Vol. VI. , by J. Watson, and in Philos. Review, 1893, by J. G. Schurmann. — E. Adickes has begun an exhaustive bibliography of the German literature in the Philos. Review, 1893. ]
The citations refer to the older Hartenstein edition In the case of many works the convenient editions by K. Kehrbach (Reclam. Bib. ) make easy the transfer of the citations to the other editions.
given in Ueberweg, II. 138 (Eng. tr. )].
Complete editions of his works have been prepared by K. Kosenkranz and
1
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Chap. 1, § 38. ] Object of Knowledge. 637
§ 38. The Object of Knowledge.
Erh. Schtnid, Kritik der reinen Vernunft im Grundrisse. Jena, 1786.
H. Cohen, Kant'$ Theorie der Erfahrung. Berlin, 1871.
A. Holder, Darttellung der kantischen Erkenntnissthcorie. Tubingen, 1873.
A. Stadler, Die Grundsatxe der reinen Erkenntnisstheorie in der kantUchen
Philosuphie. Leips. 1876.
Job. Volkelt, /. Kani't Erkenntnisstheorie naeh ihren Grundprincipien analysirt.
Leips. 1879.
E. Pfleiderer, Kantischer Kriticismus und englisehe Philosophic Tubingen,
1881.
J. Hutchinson Stirling, Text-Book to Kant. Edin. and Lond. 1881.
Seb. Turbiglio, Analisi, Storia, Critica delta Bagione Pura. Rome, 1881. G. 8. Morris, Kant's Critique of Pure Beaton, Chicago, 1882.
Fr. Staudinger, Xoumena. Darmstadt, 1884.
[K. Fischer's Criticism of Kant, trans, by Hough. Lond. 1888. ]
[J. Watson, Kant and his English Critics. Lond. 1886. ]
[H. Vaihinger, Commentar zu Kant's Kritik d. r. Vernunft, II. (on the
^Esthetic). Stuttgart, 1892. ]
Kant's theory of knowledge followed with tenacious consistency from the statement which modern Terminism had given to problems
of knowledge (cf. pp. 466 and 482). The philosopher had grown up
in the naive realism of the Wolffian school, which without close scrutiny regarded logical necessity and reality as identical ; and his liberation from the ban of this school consisted in his seeing the impossibility of determining out of " pure reason," i. e. through mere logical operations with conceptions, anything whatever as to the ) existence1 or the causal relation* of real things. The metaphysi cians are the architects of many a world of thought in the air;' but their structures have no relation to reality. Kant now sought this
relation first in the conceptions given through experience, since the genetic connection of these with the reality to be known by science seemed immediately evident, but he was shaken from this "dog matic slumber" by Hume,4 who demonstrated that precisely the constitutive Forms of the conceptional knowledge of reality, espec ially the Form of causality, are not given in perception, but are
• Cf. Kant's Sole Possthlr Prooffor thr Existence of God.
* Cf. the Essay on Srgntive Magnitudes, especially the conclusion (W. , I.
ma. ).
•DreamsofaGhoMSeer,I. 3; W. ,III. 7. V
* In connection with this frequently mentioned confession of Kant, It is for the most part disregarded that he characterised as " dogmatic " not only rationalism, but also the empiricism of the earlier theory of knowledge, and that the classical passage at which he uses this expression (in the preface to the Prolegomena, W. , III. 170 f. ) does not contrast Hume with Wolff, but with
Locke, Rekl. and Hvattie only. The dogmatism from which, therefore, Kant declared that he luul been freed throuch Hume vas that of empiricism.
538 German Philosophy : Kant's Critique. [Past VI.
products of the mechanism of association without any demonstrable relation to the real. Reality was not to be known from the "given" conceptions, either. And then Kant, prompted by Leibniz, deliber ated once more whether the purified conception of virtual innate- ness, with the aid of the " pre-established harmony " grounded in God between the monad which knows and the monad which is to be known, might not solve the mystery of the relation of thought and
Being, and in his Inaugural Dissertation he had convinced himself that this was the solution of the problem. But cool reflection soon showed that this pre-established harmony was a metaphysical assumption, incapable of proof and unable to support a scientific system of philosophy. So it appeared that neither empiricism nor rationalism had solved the cardinal question, — the relation of knowl edge to its object, in what does it consist and on what does it rest ? '
1. Kant's own, long-weighed answer to this question is the Critique of Pure Reason. In its final systematic form, which found an ana lytical explication in the Prolegomena, his criticism proceeds from the fact of the actual presence of synthetic judgments a priori in three theoretical sciences ; viz. in mathematics, in pure natural science, and in metaphysics; and the design is to examine their claims to universal and necessary validity.
In this formulation of the problem the insight into the nature of reason's activity, which Kant had gained in the course of his critical ' development, came into play. This activity is synthesis, i. e. the
uniting or unifying of a manifold. * This conception of synthesis 3 is a new element which separates the Critique from the Inaugural Dis sertation ; in it Kant found the common element between the Forms of the sensibility and those of the understanding, which in his exDosition of 1770 were regarded as entirely separate, in accordance with their characteristic attributes of receptivity and spontaneity respectively. 4 It now appeared that the synthesis of the theoretical
' Kant's letter to Marcus Here, Feb. 21, 1772.
5 This frequently repeated definition makes the fundamental conception of of the critical doctrine of knowledge appear in closest proximity to the funda mental metaphysical conception of the Monadology. Cf. § 31, 11.
8 Which is introduced in the Transcendental Analytic in connection with the doctrine of the categories. Sections 10 and 15 (of the first edition of the Critique).
4 Hence the conception of synthesis in the present form of the Critique of Pure Season comes in collision with the psychological presuppositions which passed over to the Critique out of the German working-over of the Inaugural Dissertation, which forms the Transcendental ^Esthetic and the beginning of the Transcendental Logic (this was originally to have appeared immediately after 1770 under the title Limits of the Sensibility and of the Understanding). In
the Prolegomena these psychological presuppositions became obliterated. Earlier, sensibility and understanding were set over against each other as receptivity and spontaneity ; but space and time, the pure Forms of the sensi
Chap. 1, $ 38. ] Object of Knowledge : Synthesis. 539 ■
reason completes itself in three stages : the combination of sensa tions into perceptions takes place in the Forms of space and time ; the combination of the perceptions into experience of the natural world of reality takes place by means of concepts of the understand ing; the combination of judgments of experience into metaphysical knowledge takes place by means of general principles, which Kant calls Ideas. These three stages of the knowing activity develop, therefore, as different Forms of synthesis, of which each higher stage has the lower for its content.
The critique of reason has to investigate what the especial Forms of this synthesis are in each stage, and in what their universal and necessary validity consists.
2. As regards mathematics, the conception of the Inaugural Dis- ■ sertation fits aptly, in the main, into the critique of reason. Mathe matical propositions are synthetic ; they rest in the last resort upon construction in pure perception, not upon the development of con ceptions. Their necessity and universal validity, which cannot be established by any experience, is, therefore, to be explained only if an a priori priurjjilp of perception lies at their basis. Kant, there
fore, shows that the general ideas of space and time, to which all insights of geometry and arithmetic relate, are " pure Forms of per ception " or " perceptions a priori. " The ideas of the one infinite space and of the one infinite time do not rest upon th4 combination of empirical perceptions of finite spaces and times; (but with the very attributes of limit in the " beside-of-one-anotheit" and " after- one-another" (co-existence and succession), the whole of space and the whole of time respectively are already involved in the empirical perception of particular space and time magnitudes, which can accord ingly be presented to the mind only as parts of space in general and of time in general. Space and time cannot be "concepts," since they relate to an object which is only a single, unique object, and which is not thought as complete, but is involved in an infinite synthesis ; and further, they are related to the ideas of finite magni tudes, not as class-concepts are to their particular examples, but as the whole to the part. If they are, accordingly, pure perceptions
(Anscliauungen), i. e. perceptions not founded upon empirical percep tions ( Wahrnehrnungen), but lying at the basis of all empirical per ceptions,1 then they are, as such, necessary ; for we can indeed think
bility, were Indeed the principles of the synthetical ordering of the sensations, and thus belonged under the general conception of synthesis, i. e. spontaneous unity of the manifold. Thus the conception of synthesis burst the psychological schema of the Inaugural Dutertatinn.
1 Here once more it must be recalled that it is but a perverted and completely erroneous conception of Kant to conceive of this " lying at the basis of" or - preceding," as referring to time. The natMtrn, which holds space and time
540 German Philosophy : Kant' i Critique. [Part VL
everything away from them, but cannot think them away. They are the given Forms of pure perception from which we cannot escape, the laws of relations, in which alone we can mentally represent with synthetic unity the manifold of sensations. And further, space is the form of the outer sense, time that of the inner sense ; all objects of the particular senses are perceived as spatial, all objects of self- perception as in time. "
If, then, space and time are the
ous receptivity," cognitions determined by these two kinds of per ception without any regard to the particular empirical content, possess universal and necessary validity for the entire compass of all that we can perceive and experience. In the realm of the sensi bility, — so the " Transcendental ^Esthetic " teaches, — the only object of a priori knowledge is the Form of the synthesis of the man ifold given through sensation, — the law of arrangement in space and time. But the universality and necessity of this knowledge is intel ligible only if space and time are nothing but the necessary Forms oj man's sensuous perception. If they possessed a reality independent of the functions of perception, the a priori character of mathematical knowledge would be impossible. Were space and time themselves things or real properties and relations of things, then we could know of them only through experience, and, therefore, never in a univer sal and necessary way. This last mode of knowledge is possible only if they are nothing but the Form under which all things in our perception must appear. 1 According to this principle the a priori and the phenomenal become for Kant interchangeable conceptions.
The only universal and necessary element in man's knowledge is the Form under which things appear in it. Rationalism limits itself to the Form, and holds good even for this only at the price of the " subjectivity " of the same.
3. While Kant would thus have the spatial and chronological re lations of objects of perception regarded as wholly a mode of mental representation, which does not coincide with the reality of things themselves, he distinguished this conception of their ideality very exactly from that " subjectivity of the qualities of sense " which was held by him, as by all philosophy after Descartes and Locke, to be self-evident. * And the point at issue here again is solely the ground of the phenomenality. As regards colour, taste, etc. , the phenome- nality had been based, since the time of Protagoras and Democritus,
to be inborn ideas, is un-Kantian throughout, and stands in contradiction tc express declarations of the philosopher (cf. , e. g. , above, p. 465 f. ).
1 This thought is developed with especial clearness in the Prolegomena, 1 8. * Cf. Critique, § 3, b. W. , II. 68.
unchangeable Form of our sensu
Chap. 1, J 38. ] Object of Knowledge : Space and Time. 541
upon the difference and relativity of impressions ; for the Forms of space and time, Kant deduces their phenomenality precisely from ) their invariability. For him, therefore, the qualities of sense offered only an individual and contingent mode of representation ; while the Forms of space and time, on the other hand, present
a universal and necessary mode in which things appear. All that
contains, is, indeed, not the true essence of things, but an appearance or phenomenon ; but the contents of sensation are " phenomena" in quite another sense than that in which the Forms of space and time are such; the former have worth only as the states of the individual subject, the latter as " objective " Forms of perception for all. Even on this ground, therefore, Kant, too, sees the task of natural science to lie in the reduction of the qualitative to the quantitative, in which alone necessity and universal validity can be found upon a mathematical basis, agreeing in this with
Democritus and Galileo; but he differed from his predecessors in holding that, philosophically considered, even the mathematical mode of representing Nature can be regarded only as an appearance and phenomenon, though in the deeper sense of the word. Sensation gives an individual idea, mathematical theory gives a necessary, universally valid perception of the actual world; but both are merely different stages of the phenomenal appearance, behind which the true thing-in-itself remains unknown. Space and time hold without exception for all objects of perception, but for nothing beyond ; they have " empirical reality " and " transcendental ideality,"
4. The main advance of the Critique of Reason beyond the Inau gural Dissertation consists in the fact that these same principles are extended in a completely parallel investigation to the question as to the epistemological value which belongs to the synthetic Forms of the activity of the understanding. 1
Natural science needs besides its mathematical basis a number of general principles as to the connection of things. These principles, such as that every change must have its cause, are of a synthetic nature, but, at the same time, are not caj>able of being established by experience, though they come to consciousness through experi ence, are applied to experience, and find there their confirmation. Of such principles a few have indeed been incidentally propounded and treated hitherto, and it remains for the Critique itself to dis cover the "system of principles," but it is clear that without this basis the knowledge of Nature would be deprived of its necessary
1 ThU parallelism is seen most plainly by comparing ff 0 and 14 of (he Prolegomena.
perception
542 German Philosophy : Kant's Critique. [Pakt VL
and univerSal validity. For " Nature " is not merely an aggregate of spatial and temporal Forms, of corporeal shapes and motions, but a connected system, which we perceive through our senses, but thinh at the same time through conceptions. Kant calls the faculty of thinking the manifold of perception in synthetic unity, the Understanding; and the categories or pure conceptions of Understand ing are the Forms of the synthesis of the Understanding, just as space and time are the Forms of the synthesis of perception.
If now Nature, as object of our knowledge, were a real connected system of things, independent of the functions of our reason, we could know of it only through experience and never o priori; a uni versal and necessary knowledge of Nature is possible only if our conceptional Forms of synthesis determine Nature itself. If Nature prescribed laws to our understanding, we should have only an empirical, inadequate knowledge ; an a priori knowledge of Nature is therefore possible only ifthe case be reversed and our understanding prescnbes laws to Nature. But our understanding cannot determine Nature in so far as it exists as a thing-iu-itself, or as a system of things-in-themselves, but only in so far as it appears in our thought A priori knowledge of Nature is therefore possible only ifthe con nection ichich we think between perceptions is also nothing but our mode of ideation; the conceptional relations " also, in which Nature is an object of our knowledge, must be only phenomenon. "
5. In order to attain this result, the Critique of Reason proceeds first to assure itself of these synthetic Forms of the understanding in systematic completeness. Here it is clear from the outset that we have not to do with those analytic relations which are treated in formal logic, and grounded upon the principle of contradiction. For
ese contain only the rules for establishing relations between con ceptions according to the contents already given within them. But such modes of combination as are present when we affirm the rela tion of cause and effect, or of substance and accident, are not con tained in those analytical Forms — just this had been shown by Hume. Kant discovers here the completely new task of transcendental logic} Side by side with the (analytic) Forms of the understanding, in accordance with which the relations of conceptions which are given as to their contents are established, appear the synthetic Forms of understanding, through which perceptions are made objects of conceptional knowledge. Images of sensation, co-ordinate in space and changing in time, become "objective" only by being thought as
' Cf. M. Steckelmacher, Die formate Logik Kant's in ihren Beziehungen zva transscendentalen (Breslau, 1878).
Chap. 1, | 38. ] Object of Knowledge : Categories 648
things with abiding qualities and changing states ; but this relation expressed by means of the category inheres analytically neither in the perceptions nor in their perceptional relations as such. In the ana lytic relations of formal logic thinking is dependent upon its objects, and appears ultimately with right as only a reckoning with given magnitudes. The synthetic Forms of transcendental logic, on the contrary, let us recognise the understanding in its creative function of producing out of perceptions the objects of thought itself.
At this point, in the distinction between formal and transcen dental logic, appears for the first time the fundamental antithesis between Kant and the conceptions of the Greek theory of knowl edge which had prevailed up to his time. The Greek theory assumed " the objects " as " given " independently of thought, and regarded the intellectual processes as entirely dependent upon the objects; at the most it was the mission of the intellectual processes to reproduce these objects by way of copy, or allow themselves to be guided by them. Kant discovered that the objects of thought are none other than the products of thought itself. This spontaneity of reason forms the deepest kernel of his transcendental idealism.
But while he thus with completely clear consciousness set a new epistemological logic of synthesis by the side of the analytical logic of Aristotle, which had as its essential content the relations involved in subsuming ready-made conceptions under each other (cf. § 12), he yet held that both had a common element, viz: the science of
judgment. In the judgment the relation thought between subject and predicate is asserted as holding objectively ; all objective think ing is judging. Hence if the categories or radical concejitions of the understanding are to be regarded as the relating forms of the synthesis by which objects arise, there must be as many categories as there are kinds of judgments, and every category is the mode of connecting subject and predicate which is operative in its own kind of judgment.
Kant accordingly thought that he could deduce the table of the categories from that of the judgments. He distinguished from the four points of view of Quantity, Quality, Relation, and Modality, three kinds of judgments for each: Universal, Particular, Singular, — Affirmative, Negative, Infinite, — Categorical, Hypothetical, Dis junctive, — Problematic, Assertoric, Apodictic; and to these were to correspond the twelve categories: Unity, Plurality, Totality, —
Reality, Negation, Limitation. — Inherence and Subsistence, Caus ality and Dependence, Community or Reciprocity, — Possibility and Impossibility, Existence and Non-existence, Necessity and Con
tingency.
The artificiality of this construction, the looseness of
544 German Philosophy : Kant's Critique. [Part VL
the relations between Forms of judgment and categories, the un equal value of the categories, — all this is evident, but Kant unfortunately had so much confidence in this system that he treated it as the architectonic frame for a great number of his later investigations.
6. The most difficult part of the task, however, was to demon strate in the "Transcendental Deduction of the Pure Conceptions of the Understanding" how the categories "make the objects of experience. " The obscurity into which the profound investigation of the philosopher necessarily came here is best brightened
a fortunate idea of the Prolegomena. Kant here distinguishes judg ments ofperception, i. e. those in which only the relation of sensations in space and time for the individual consciousness is expressed, and
judgments of experience, i. e. those in which such a relation is asserted as objectively valid, as given in the object; and he finds . the difference in epistemological value between them to be, that in the judgment of experience the spatial or temporal relation is
regulated and grounded by a category, a conceptional connection, whereas in the mere judgment of perception this is lacking. Thus, for example, the succession of two sensations becomes objective and universally valid when it is thought as having its ground in the fact that one phenomenon is the cause of the other. All particular constructions of the spatial and temporal synthesis of sensations become objects only by being combined accordiug to a rule of the understanding. In contrast with the individual mechanism of
This is especially true in the case of relations in time. For since phenomena of outer sense belong to the inner sense as "determina tions of our mind," all phenomena without exception stand under the Form of the inner sense, i. e. of time. Kant, therefore, sought to show that between the categories and the particular Form of perception in time a " schematism " obtains, which first makes it possible at all to apply the Forms of the understanding to the images of perception, and which consists in the possession by every individual category of a schematic similarity with a particular form of the time relation. In empirical knowledge we use this schematism to interpret the empirically perceived time relation by the correspond ing category [e. g. to apprehend regular succession as causality] ; transcendental philosophy, conversely, has to seek the justification
ideation, in which individual sensations may order
separate and unite in any way whatever, stands objective think ing, which is equally valid for all, and is bound to fixed, co herent, ordered wholes, in which the connections are governed by conceptions.
themselves,
up by
Chap. 1, J 38. ] Object of Knowledge : Experience. 545
of this procedure in the fact that the category, as a rule of the understanding, gives the corresponding time relations a rational basis as object of experience.
In fact, the individual consciousness finds in itself the contiast between a movement of ideas (say of the fancy), for which it claims no validity beyond its own sphere, and, on the other hand, an activ ity of experience, in the case of which it knows itself to be bound in a way that is likewise valid for all others. Only in this depend ence consists the reference of thought to an object. But if it was now recognised that the ground of the objective validity of the time (and space) relation can rest only in its determination by a rule of the understanding, it is on the other hand a fact that the consciousness of the individual knows nothing of this co-opera tion of the categories in experience, and that he rather accepts the
result of this co-operation as the objective necessity of his appre hension of the synthesis of sensations in space and time.
The production of the object, therefore, does not go on in the individual consciousness, but lies already at the basis of this con sciousness ; for this production, a higher common consciousness must therefore be assumed, which comes into the empirical consciousness of the individual, not with its functions, but only with their result. This Kant termed in the Prolegomena, consciousness in general; in the" Critique, transcendental appeixeption, or the "I" [or l'self" or ego"]. *
Experience is accordingly the system of phenomena in which the l spatial and temporal synthesis of sensation is determined by the rules \ of the understanding. Thus " Nature as phenomenon " is the object
of an a priori knowledge ; for the categories hold for all experience, ' / because experience is grounded only through them.
7. The universal and necessary force and validity of the cate gories find expression in the Principles of the Pure Understanding, in which the conceptional Forms unfold themselves through the medium of the schematism. But here it is at once evident that the main weight of the Kantian doctrine of the categories falls upon the third group, and thus upon those problems in which he hoped '•to solve Hume's doubt. " From the categories of Quantity and Quality result only the " Axiom of Perception," that all phenomena are extensive magnitudes, and the " Anticipations of Empirical Perception " according to which the object of sensation is an inten sive magnitude ; in the case of Modality there result only definitions of the possible, actual, and necessary, under the name of the '' Postu lates of Empirical Thought. " On the other hand, the Analogies of Experience prove that in Nature substance is permanent, and that
546 German Philosophy : Kant's Critique. [Past VL
its quantum can be neither increased nor diminished, that all changes take place according to the law of cause and effect, and that all substances are in thorough-going reciprocity or inter-action.
. These, therefore, are the universally and necessarily valid, prin-
/ciples and highest premises of all natural science, which are uni- / versally and necessarily valid without any empirical proof j they / contain what Kant calls the metaphysics of Nature. In order that they may be employed, however, upon the Nature given through
[
1 our senses, they must pass through a mathematical formulation,
I because Nature is the system of sensations perceived in the Forms
of space and time and ordered according to the categories. This transition is effected through the empirical conception of motion, to which all occurrence and change in Nature is theoretically to be reduced. At least, science of Nature, in the proper sense, reaches only so far as we can employ mathematics : hence Kant excluded psychology and chemistry from natural science as being merely descriptive disciplines. The "Metaphysical Elements of Natural Science " contain, accordingly, all that can be inferred universally and necessarily concerning the laws of motion, on the ground of the categories and of mathematics. The most important point in Kant's
philosophy of Nature, as thus built up, is his dynamic theory of mat ter, in which he now deduces from the general principles of the Critique the doctrine already laid down in the " Natural History of the Heavens," that the substance of that which is movable in space is the product of two forces which maintain an equilibrium in a
varying degree, — those of attraction and repulsion.
8. But in accordance with Kant's presuppositions, the above
metaphysics of Nature can be only a metaphysics of phenomena : and no other is possible, for the categories are Forms for relating, and as such are in themselves empty ; they can refer to an object only through the medium of perceptions, which present a manifold
content to be combined. This perception, however, in the case of us men, only the sensuous perception in the forms of space and time, and as content for their synthetic function we have only that given in sensations. Accordingly, the only object of human knowledge is experience, i. e. phenomenal appearance and the divis ion of objects of knowledge into phenomena and noumena, which has been usual since Plato, has no sense. A knowledge of things-in- themselves through " sheer reason," and extending beyond experi ence, nonentity, chimera.
But has, then, the conception of the thing-in-itself any rational meaning at all and not, together with this, the designation all objects of our knowledge as " phenomena," also without meaning?
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a
a is
of
is a
;
is,
Chap. 1, §38. ] Object of Knowledge : Thing-in-Itsclf. 647
This question was the turning-point of Kant's reflections.
all that the naive conception of the world regards as " object " has been resolved partly into sensations, partly into synthetic Forms of perception and of the understanding; nothing seems to remain besides the individual consciousness as truly existing, except the
" consciousness in general," the transcendental apperception. But where, then, are the " things," of which Kant declared that it had never come into his mind to deny their reality ?
i l
The conception of the thing-in-itself can, to be sure, no longer have a positive content in the Critique of Reason, as it had with Leibniz, or in Kant's Inaugural Dissertation ; it can no longer be the object of purely rational knowledge, it can no longer be an "object" at all.
But it is at least no contradiction, merely to think it
purely hypothetically, and as something the reality of which is
neither to be affirmed nor to be denied, — a mere
Human knowledge is limited to objects of experience, because the perception required for the use of the categories is in our case only
< that there is another kind of ]>ercpption, there would be for this / /
other objects, likewise, with the help of the categories. Such objects of a non-human perception, however, remain still only phenomena, though this perception again might be assumed as one which arranges the given contents of sensation in any manner whatever.
Nevertheless, if one should think of a perception of a non-receptive kitid, a perception which synthetically produced not only its Forms, but also its contents, — a truly "productive imagination," — its objects would necessarily be no longer phenomena, but things-in- themselves. Such a faculty would deserve the name of an intellect ual perception (or intuition), or intuitive intellect; it would be the unity of the two knowing faculties of sensibility and understand ing, which in man appear separated, although by their constant reference to each other they indicate a hidden common root. The possibility of such a faculty is as little to be denied as its reality is to be affirmed ; yet Kant here indicates that we should have to think a supreme spiritual Being in this way. Noumena, or things- in-themselves, are therefore thinkable in the. negative tense as objects of a non-sensuous perception, of which, to be sure, our knowledge can predicate absolutely nothing, — they are thinkable as limiting con ceptions of experience.
And ultimately they do not remain so completely problematical| :i* would at first appear. For if we should deny the reality of things-in-themselves, "all would be immediately resolved into phenomena," and we should thus be venturing the assertion that
'
Hitherto
Primarily,
" problem. "
j
the receptive sensuous perception in space and time. If we suppose 1
^\
648 Oerman Philosophy : Kant* Critique. [Part VL
nothing is real except what appears to man, or to other sensuously receptive beings. But this assertion would be a presumption com pletely incapable of proof. Transcendental idealism must, therefore, not deny the reality of noumena; it must only remain conscious that they cannot in any wise become objects' of human knowledge. Things-in-themselves must be thought, but are not knowable. In this way Kant won back the right to designate the objects of human knowledge as "only phenomena. "
9. With this the way was marked out for the third part of the critique of the reason, the Transcendental Dialectic. 1 A metaphysics of that whioh cannot be experienced, or, as Kant prefers to say, of the supersensuous, is impossible. This must be shown by a criticism of the historical attempts which have been made with this in view, and Kant chose, as his actual example for this, the Leibnizo- Wolffian school-metaphysics, with its treatment of rational psychology, cos mology, and theology. But at the same time, it must be shown that that which is incapable of being experienced, which cannot be known, must yet necessarily be thought ; and the transcendental illusion must be discovered, by which even the great thinkers have at all times been seduced into regarding this, which must necessarily be thought, as an object of possible knowledge.
To attain this end Kant proceeds from the antithesis between the activity of the understanding and the sensuous perception by the aid of which alone the former produces objective knowledge. The thinking, which is determined by the categories, puts the data of the sensibility into relation with one another in such a way, that every phenomenon is conditioned by other phenomena : but in this process the understanding, in order to think the individual phenom enon completely, must needs grasp the totality of the conditions by which this particular phenomenon is determined in its connection* with the whole experience. But, in view of the endlessness of the world of phenomena in its relation to space and time, this demand cannot be fulfilled. For the categories are principles of relation between phenomena ; they cognise the eonditionality or conditional character of each phenomenon only by means of other phenomena, and demand for these again insight into their conditional nature as determined by others, and so on to infinity. ' Out of this relation
» As regards the subject matter, the Transcendental Esthetic Analytic, aai Dialetic. as the Introduction shows, form the three main co-ordinate para of the Critin** . ' the formal schematism of the dirision which Kant imitated froai the arrangement of logical text-books usual at that time, is, on the contrary. entirely irrelevant. The •' Doctrine of Method " is in fact only a supplement extremely rich in tine observations.
* Of. the similar thoughts in Xkolaus Cusanus and Spinoxa. though then metaphysically applied : above, pp. $47 and 419.
Ciiah. 1, § 38. ] Object of Knoicledye : Idea*. 649
between understanding and sensibility result for human knowledge necessary and yet insoluble problems; these Kant calls Ideas, and the faculty requisite for this highest synthesis of the cognitions of the understanding he designates as Reason in the narrower sense.
If now the reason will represent to itself as solved, a problem thus set, the sought totality of conditions must be thought as some l thing unconditioned, which, indeed, contains in itself the conditions
for the infinite series of phenomena, but which is itself no longer conditioned. This conclusion of an infinite series, which for the knowledge of the understanding is in itself a contradiction, must nevertheless be thought, if the task of the understanding, which L aims at totality in connection with the infinite material of the data
of the senses, is to be regarded as performed. The Ideas are hence ideas or mental representations of the unconditioned, which must necessarily be thought without ever becoming object of knowledge,
and the transcendental illusion into which metaphysics falls con sists in regarding them as given, whereas they are only imposed or
set as a task (aufgegeben). In truth they are not constitutive prin ciples through which, as through the categories, objects of knowl edge are produced, but only regulative principles, by which the understanding is constrained to seek for farther and farther con necting links in the realm of the conditioned of experience.
Of such Ideas Kant finds three ; the unconditioned for the totality of all phenomena of the inner sense, of all data of the outer sense, of all the conditioned in general, is thought respectively as the soul, the world, and Ood.
10. The criticism of rational psychology in the " Paralogisms of Pure Reason " takes the form of pointing out in the usual proofs for the substantiality of the soul, the quaternio terminorum of a confusion of the logical subject with the real substrate ; it shows that the scientific conception of substance is bound to our perception of that which persists in space, and that it is therefore applicable only in the field of the external sense, and maintains that the Idea of the soul as an unconditioned real uuity of all phenomena of the inner sense, is indeed as little capable of proof as it is of refutation, but is at the same time the heuristic principle for investigating the inter-connections of the psychical life. " "
In a similar way, the section on the Ideal of the Reason
treats the Idea of God. Carrying out with greater precision his earlier
treatise on the same subject, Kant destroys the cogency of the arguments brought forward for the existence of God. He combats the right of the ontological proof to infer existence from the concep-
650 German Philosophy : Kant'* Critique. [Part VL
tion alone ; he shows that the cosmological proof involves a petitio prindpii when it seeks the " first cause " of all that is "contingent " in an " absolutely necessary " being ; he proves that the teleological or physico-tAeological argument at the best — granted the beauty, harmony, and purposiveness or adaptation of the universe —leads to the ancient conception of a wise and good '* Architect of the world. " But he emphasises that the denial of God's existence is a
claim which steps beyond the bounds of our experiential knowledge, and is as incapable of proof as the opposite, and that rather the belief in a living, Real unity of all reality constitutes the only powerful motive for empirical investigation of individual groups of phenomena.
Most characteristic by far, however, is Kant's treatment of the Idea of the world in the Antinomies of Pure Reason.
1876).
Cf. also
The additional main writings of Kant in his critical period are Prolegomena zu einer jeden kUnftigen Metaphysik, 1783 Grundlegung zur Metaphysik der Sitten, 1785 Metaphysische Anfangsgrunde der Naturwissenschafl, 1785 Kritik der praktischen Vernunft, 1788 Kritik der Vrtheilskraft, 1790 Die Religion innerhalb der Grenzen der blossen Vernunft, 1793 Zum ewigen Frie- den, 1796 Metaphysische Anfangsgriinde der Rechts- und Tugendlehre, 1797 Der Streit der FakultSten, 1798 [Eng. tr. of the Prolegomena, by Mahaffy and Bernard, Lond. and N. Y. 1889; of the Prolegomena and Metaphysical Founda tions of Natural Science, by Bax, Bohn Library of the ethical writings, includ ing the first part of the Religion within the Bounds of Pure Reason, by T. K Abbott, 4th ed. , Lond. 1889 of the Critique of Judgment, by J. H. Bernard, Lond. and N. Y. 1892; of the Philosophy of Law, by W. Hastie, Edin. 1887; Principles of Politics, including the essay on Perpetual Peace, by W. Hastie, Edin. 1891. The contents of Kant's Essays and Treatises, vols. , Lond. 1798,
F. W. Schubert (12 vols. , Leips. 1833 ff. ), G. Hanenstein (10 vols. , Leips. 1838 f. , and recently vols. , Leips. 1867 ff. ), and J. v. Kirchmann (in the Philos. Biblioth. ). 1 They contain, besides his smaller articles, etc. , his lectures upon logic, pedagogy, etc. , and his letters. A survey of all that has been written by Kant (including also the manuscript of the Transition from Meta physics to Physics, which without value for the interpretation of his critical system) found in Ueberweg- Heinze, III. 24 there, too, the voluminous literature cited with great completeness. Of this we can give here only a choice of the best and most instructive survey of the more, valuable literature, arranged according to its material, offered by the article Kant, by W. Windel band in Ersch und Gruber's Enc. [The Journal of Speculative Philosophy contains numerous articles upon Kant. We may mention also Adamson, The Philosophy of Kant, Edin. 1879; art. Kant, in Enc. Brit. , by the same author; arts, in Mind, Vol. VI. , by J. Watson, and in Philos. Review, 1893, by J. G. Schurmann. — E. Adickes has begun an exhaustive bibliography of the German literature in the Philos. Review, 1893. ]
The citations refer to the older Hartenstein edition In the case of many works the convenient editions by K. Kehrbach (Reclam. Bib. ) make easy the transfer of the citations to the other editions.
given in Ueberweg, II. 138 (Eng. tr. )].
Complete editions of his works have been prepared by K. Kosenkranz and
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Chap. 1, § 38. ] Object of Knowledge. 637
§ 38. The Object of Knowledge.
Erh. Schtnid, Kritik der reinen Vernunft im Grundrisse. Jena, 1786.
H. Cohen, Kant'$ Theorie der Erfahrung. Berlin, 1871.
A. Holder, Darttellung der kantischen Erkenntnissthcorie. Tubingen, 1873.
A. Stadler, Die Grundsatxe der reinen Erkenntnisstheorie in der kantUchen
Philosuphie. Leips. 1876.
Job. Volkelt, /. Kani't Erkenntnisstheorie naeh ihren Grundprincipien analysirt.
Leips. 1879.
E. Pfleiderer, Kantischer Kriticismus und englisehe Philosophic Tubingen,
1881.
J. Hutchinson Stirling, Text-Book to Kant. Edin. and Lond. 1881.
Seb. Turbiglio, Analisi, Storia, Critica delta Bagione Pura. Rome, 1881. G. 8. Morris, Kant's Critique of Pure Beaton, Chicago, 1882.
Fr. Staudinger, Xoumena. Darmstadt, 1884.
[K. Fischer's Criticism of Kant, trans, by Hough. Lond. 1888. ]
[J. Watson, Kant and his English Critics. Lond. 1886. ]
[H. Vaihinger, Commentar zu Kant's Kritik d. r. Vernunft, II. (on the
^Esthetic). Stuttgart, 1892. ]
Kant's theory of knowledge followed with tenacious consistency from the statement which modern Terminism had given to problems
of knowledge (cf. pp. 466 and 482). The philosopher had grown up
in the naive realism of the Wolffian school, which without close scrutiny regarded logical necessity and reality as identical ; and his liberation from the ban of this school consisted in his seeing the impossibility of determining out of " pure reason," i. e. through mere logical operations with conceptions, anything whatever as to the ) existence1 or the causal relation* of real things. The metaphysi cians are the architects of many a world of thought in the air;' but their structures have no relation to reality. Kant now sought this
relation first in the conceptions given through experience, since the genetic connection of these with the reality to be known by science seemed immediately evident, but he was shaken from this "dog matic slumber" by Hume,4 who demonstrated that precisely the constitutive Forms of the conceptional knowledge of reality, espec ially the Form of causality, are not given in perception, but are
• Cf. Kant's Sole Possthlr Prooffor thr Existence of God.
* Cf. the Essay on Srgntive Magnitudes, especially the conclusion (W. , I.
ma. ).
•DreamsofaGhoMSeer,I. 3; W. ,III. 7. V
* In connection with this frequently mentioned confession of Kant, It is for the most part disregarded that he characterised as " dogmatic " not only rationalism, but also the empiricism of the earlier theory of knowledge, and that the classical passage at which he uses this expression (in the preface to the Prolegomena, W. , III. 170 f. ) does not contrast Hume with Wolff, but with
Locke, Rekl. and Hvattie only. The dogmatism from which, therefore, Kant declared that he luul been freed throuch Hume vas that of empiricism.
538 German Philosophy : Kant's Critique. [Past VI.
products of the mechanism of association without any demonstrable relation to the real. Reality was not to be known from the "given" conceptions, either. And then Kant, prompted by Leibniz, deliber ated once more whether the purified conception of virtual innate- ness, with the aid of the " pre-established harmony " grounded in God between the monad which knows and the monad which is to be known, might not solve the mystery of the relation of thought and
Being, and in his Inaugural Dissertation he had convinced himself that this was the solution of the problem. But cool reflection soon showed that this pre-established harmony was a metaphysical assumption, incapable of proof and unable to support a scientific system of philosophy. So it appeared that neither empiricism nor rationalism had solved the cardinal question, — the relation of knowl edge to its object, in what does it consist and on what does it rest ? '
1. Kant's own, long-weighed answer to this question is the Critique of Pure Reason. In its final systematic form, which found an ana lytical explication in the Prolegomena, his criticism proceeds from the fact of the actual presence of synthetic judgments a priori in three theoretical sciences ; viz. in mathematics, in pure natural science, and in metaphysics; and the design is to examine their claims to universal and necessary validity.
In this formulation of the problem the insight into the nature of reason's activity, which Kant had gained in the course of his critical ' development, came into play. This activity is synthesis, i. e. the
uniting or unifying of a manifold. * This conception of synthesis 3 is a new element which separates the Critique from the Inaugural Dis sertation ; in it Kant found the common element between the Forms of the sensibility and those of the understanding, which in his exDosition of 1770 were regarded as entirely separate, in accordance with their characteristic attributes of receptivity and spontaneity respectively. 4 It now appeared that the synthesis of the theoretical
' Kant's letter to Marcus Here, Feb. 21, 1772.
5 This frequently repeated definition makes the fundamental conception of of the critical doctrine of knowledge appear in closest proximity to the funda mental metaphysical conception of the Monadology. Cf. § 31, 11.
8 Which is introduced in the Transcendental Analytic in connection with the doctrine of the categories. Sections 10 and 15 (of the first edition of the Critique).
4 Hence the conception of synthesis in the present form of the Critique of Pure Season comes in collision with the psychological presuppositions which passed over to the Critique out of the German working-over of the Inaugural Dissertation, which forms the Transcendental ^Esthetic and the beginning of the Transcendental Logic (this was originally to have appeared immediately after 1770 under the title Limits of the Sensibility and of the Understanding). In
the Prolegomena these psychological presuppositions became obliterated. Earlier, sensibility and understanding were set over against each other as receptivity and spontaneity ; but space and time, the pure Forms of the sensi
Chap. 1, $ 38. ] Object of Knowledge : Synthesis. 539 ■
reason completes itself in three stages : the combination of sensa tions into perceptions takes place in the Forms of space and time ; the combination of the perceptions into experience of the natural world of reality takes place by means of concepts of the understand ing; the combination of judgments of experience into metaphysical knowledge takes place by means of general principles, which Kant calls Ideas. These three stages of the knowing activity develop, therefore, as different Forms of synthesis, of which each higher stage has the lower for its content.
The critique of reason has to investigate what the especial Forms of this synthesis are in each stage, and in what their universal and necessary validity consists.
2. As regards mathematics, the conception of the Inaugural Dis- ■ sertation fits aptly, in the main, into the critique of reason. Mathe matical propositions are synthetic ; they rest in the last resort upon construction in pure perception, not upon the development of con ceptions. Their necessity and universal validity, which cannot be established by any experience, is, therefore, to be explained only if an a priori priurjjilp of perception lies at their basis. Kant, there
fore, shows that the general ideas of space and time, to which all insights of geometry and arithmetic relate, are " pure Forms of per ception " or " perceptions a priori. " The ideas of the one infinite space and of the one infinite time do not rest upon th4 combination of empirical perceptions of finite spaces and times; (but with the very attributes of limit in the " beside-of-one-anotheit" and " after- one-another" (co-existence and succession), the whole of space and the whole of time respectively are already involved in the empirical perception of particular space and time magnitudes, which can accord ingly be presented to the mind only as parts of space in general and of time in general. Space and time cannot be "concepts," since they relate to an object which is only a single, unique object, and which is not thought as complete, but is involved in an infinite synthesis ; and further, they are related to the ideas of finite magni tudes, not as class-concepts are to their particular examples, but as the whole to the part. If they are, accordingly, pure perceptions
(Anscliauungen), i. e. perceptions not founded upon empirical percep tions ( Wahrnehrnungen), but lying at the basis of all empirical per ceptions,1 then they are, as such, necessary ; for we can indeed think
bility, were Indeed the principles of the synthetical ordering of the sensations, and thus belonged under the general conception of synthesis, i. e. spontaneous unity of the manifold. Thus the conception of synthesis burst the psychological schema of the Inaugural Dutertatinn.
1 Here once more it must be recalled that it is but a perverted and completely erroneous conception of Kant to conceive of this " lying at the basis of" or - preceding," as referring to time. The natMtrn, which holds space and time
540 German Philosophy : Kant' i Critique. [Part VL
everything away from them, but cannot think them away. They are the given Forms of pure perception from which we cannot escape, the laws of relations, in which alone we can mentally represent with synthetic unity the manifold of sensations. And further, space is the form of the outer sense, time that of the inner sense ; all objects of the particular senses are perceived as spatial, all objects of self- perception as in time. "
If, then, space and time are the
ous receptivity," cognitions determined by these two kinds of per ception without any regard to the particular empirical content, possess universal and necessary validity for the entire compass of all that we can perceive and experience. In the realm of the sensi bility, — so the " Transcendental ^Esthetic " teaches, — the only object of a priori knowledge is the Form of the synthesis of the man ifold given through sensation, — the law of arrangement in space and time. But the universality and necessity of this knowledge is intel ligible only if space and time are nothing but the necessary Forms oj man's sensuous perception. If they possessed a reality independent of the functions of perception, the a priori character of mathematical knowledge would be impossible. Were space and time themselves things or real properties and relations of things, then we could know of them only through experience, and, therefore, never in a univer sal and necessary way. This last mode of knowledge is possible only if they are nothing but the Form under which all things in our perception must appear. 1 According to this principle the a priori and the phenomenal become for Kant interchangeable conceptions.
The only universal and necessary element in man's knowledge is the Form under which things appear in it. Rationalism limits itself to the Form, and holds good even for this only at the price of the " subjectivity " of the same.
3. While Kant would thus have the spatial and chronological re lations of objects of perception regarded as wholly a mode of mental representation, which does not coincide with the reality of things themselves, he distinguished this conception of their ideality very exactly from that " subjectivity of the qualities of sense " which was held by him, as by all philosophy after Descartes and Locke, to be self-evident. * And the point at issue here again is solely the ground of the phenomenality. As regards colour, taste, etc. , the phenome- nality had been based, since the time of Protagoras and Democritus,
to be inborn ideas, is un-Kantian throughout, and stands in contradiction tc express declarations of the philosopher (cf. , e. g. , above, p. 465 f. ).
1 This thought is developed with especial clearness in the Prolegomena, 1 8. * Cf. Critique, § 3, b. W. , II. 68.
unchangeable Form of our sensu
Chap. 1, J 38. ] Object of Knowledge : Space and Time. 541
upon the difference and relativity of impressions ; for the Forms of space and time, Kant deduces their phenomenality precisely from ) their invariability. For him, therefore, the qualities of sense offered only an individual and contingent mode of representation ; while the Forms of space and time, on the other hand, present
a universal and necessary mode in which things appear. All that
contains, is, indeed, not the true essence of things, but an appearance or phenomenon ; but the contents of sensation are " phenomena" in quite another sense than that in which the Forms of space and time are such; the former have worth only as the states of the individual subject, the latter as " objective " Forms of perception for all. Even on this ground, therefore, Kant, too, sees the task of natural science to lie in the reduction of the qualitative to the quantitative, in which alone necessity and universal validity can be found upon a mathematical basis, agreeing in this with
Democritus and Galileo; but he differed from his predecessors in holding that, philosophically considered, even the mathematical mode of representing Nature can be regarded only as an appearance and phenomenon, though in the deeper sense of the word. Sensation gives an individual idea, mathematical theory gives a necessary, universally valid perception of the actual world; but both are merely different stages of the phenomenal appearance, behind which the true thing-in-itself remains unknown. Space and time hold without exception for all objects of perception, but for nothing beyond ; they have " empirical reality " and " transcendental ideality,"
4. The main advance of the Critique of Reason beyond the Inau gural Dissertation consists in the fact that these same principles are extended in a completely parallel investigation to the question as to the epistemological value which belongs to the synthetic Forms of the activity of the understanding. 1
Natural science needs besides its mathematical basis a number of general principles as to the connection of things. These principles, such as that every change must have its cause, are of a synthetic nature, but, at the same time, are not caj>able of being established by experience, though they come to consciousness through experi ence, are applied to experience, and find there their confirmation. Of such principles a few have indeed been incidentally propounded and treated hitherto, and it remains for the Critique itself to dis cover the "system of principles," but it is clear that without this basis the knowledge of Nature would be deprived of its necessary
1 ThU parallelism is seen most plainly by comparing ff 0 and 14 of (he Prolegomena.
perception
542 German Philosophy : Kant's Critique. [Pakt VL
and univerSal validity. For " Nature " is not merely an aggregate of spatial and temporal Forms, of corporeal shapes and motions, but a connected system, which we perceive through our senses, but thinh at the same time through conceptions. Kant calls the faculty of thinking the manifold of perception in synthetic unity, the Understanding; and the categories or pure conceptions of Understand ing are the Forms of the synthesis of the Understanding, just as space and time are the Forms of the synthesis of perception.
If now Nature, as object of our knowledge, were a real connected system of things, independent of the functions of our reason, we could know of it only through experience and never o priori; a uni versal and necessary knowledge of Nature is possible only if our conceptional Forms of synthesis determine Nature itself. If Nature prescribed laws to our understanding, we should have only an empirical, inadequate knowledge ; an a priori knowledge of Nature is therefore possible only ifthe case be reversed and our understanding prescnbes laws to Nature. But our understanding cannot determine Nature in so far as it exists as a thing-iu-itself, or as a system of things-in-themselves, but only in so far as it appears in our thought A priori knowledge of Nature is therefore possible only ifthe con nection ichich we think between perceptions is also nothing but our mode of ideation; the conceptional relations " also, in which Nature is an object of our knowledge, must be only phenomenon. "
5. In order to attain this result, the Critique of Reason proceeds first to assure itself of these synthetic Forms of the understanding in systematic completeness. Here it is clear from the outset that we have not to do with those analytic relations which are treated in formal logic, and grounded upon the principle of contradiction. For
ese contain only the rules for establishing relations between con ceptions according to the contents already given within them. But such modes of combination as are present when we affirm the rela tion of cause and effect, or of substance and accident, are not con tained in those analytical Forms — just this had been shown by Hume. Kant discovers here the completely new task of transcendental logic} Side by side with the (analytic) Forms of the understanding, in accordance with which the relations of conceptions which are given as to their contents are established, appear the synthetic Forms of understanding, through which perceptions are made objects of conceptional knowledge. Images of sensation, co-ordinate in space and changing in time, become "objective" only by being thought as
' Cf. M. Steckelmacher, Die formate Logik Kant's in ihren Beziehungen zva transscendentalen (Breslau, 1878).
Chap. 1, | 38. ] Object of Knowledge : Categories 648
things with abiding qualities and changing states ; but this relation expressed by means of the category inheres analytically neither in the perceptions nor in their perceptional relations as such. In the ana lytic relations of formal logic thinking is dependent upon its objects, and appears ultimately with right as only a reckoning with given magnitudes. The synthetic Forms of transcendental logic, on the contrary, let us recognise the understanding in its creative function of producing out of perceptions the objects of thought itself.
At this point, in the distinction between formal and transcen dental logic, appears for the first time the fundamental antithesis between Kant and the conceptions of the Greek theory of knowl edge which had prevailed up to his time. The Greek theory assumed " the objects " as " given " independently of thought, and regarded the intellectual processes as entirely dependent upon the objects; at the most it was the mission of the intellectual processes to reproduce these objects by way of copy, or allow themselves to be guided by them. Kant discovered that the objects of thought are none other than the products of thought itself. This spontaneity of reason forms the deepest kernel of his transcendental idealism.
But while he thus with completely clear consciousness set a new epistemological logic of synthesis by the side of the analytical logic of Aristotle, which had as its essential content the relations involved in subsuming ready-made conceptions under each other (cf. § 12), he yet held that both had a common element, viz: the science of
judgment. In the judgment the relation thought between subject and predicate is asserted as holding objectively ; all objective think ing is judging. Hence if the categories or radical concejitions of the understanding are to be regarded as the relating forms of the synthesis by which objects arise, there must be as many categories as there are kinds of judgments, and every category is the mode of connecting subject and predicate which is operative in its own kind of judgment.
Kant accordingly thought that he could deduce the table of the categories from that of the judgments. He distinguished from the four points of view of Quantity, Quality, Relation, and Modality, three kinds of judgments for each: Universal, Particular, Singular, — Affirmative, Negative, Infinite, — Categorical, Hypothetical, Dis junctive, — Problematic, Assertoric, Apodictic; and to these were to correspond the twelve categories: Unity, Plurality, Totality, —
Reality, Negation, Limitation. — Inherence and Subsistence, Caus ality and Dependence, Community or Reciprocity, — Possibility and Impossibility, Existence and Non-existence, Necessity and Con
tingency.
The artificiality of this construction, the looseness of
544 German Philosophy : Kant's Critique. [Part VL
the relations between Forms of judgment and categories, the un equal value of the categories, — all this is evident, but Kant unfortunately had so much confidence in this system that he treated it as the architectonic frame for a great number of his later investigations.
6. The most difficult part of the task, however, was to demon strate in the "Transcendental Deduction of the Pure Conceptions of the Understanding" how the categories "make the objects of experience. " The obscurity into which the profound investigation of the philosopher necessarily came here is best brightened
a fortunate idea of the Prolegomena. Kant here distinguishes judg ments ofperception, i. e. those in which only the relation of sensations in space and time for the individual consciousness is expressed, and
judgments of experience, i. e. those in which such a relation is asserted as objectively valid, as given in the object; and he finds . the difference in epistemological value between them to be, that in the judgment of experience the spatial or temporal relation is
regulated and grounded by a category, a conceptional connection, whereas in the mere judgment of perception this is lacking. Thus, for example, the succession of two sensations becomes objective and universally valid when it is thought as having its ground in the fact that one phenomenon is the cause of the other. All particular constructions of the spatial and temporal synthesis of sensations become objects only by being combined accordiug to a rule of the understanding. In contrast with the individual mechanism of
This is especially true in the case of relations in time. For since phenomena of outer sense belong to the inner sense as "determina tions of our mind," all phenomena without exception stand under the Form of the inner sense, i. e. of time. Kant, therefore, sought to show that between the categories and the particular Form of perception in time a " schematism " obtains, which first makes it possible at all to apply the Forms of the understanding to the images of perception, and which consists in the possession by every individual category of a schematic similarity with a particular form of the time relation. In empirical knowledge we use this schematism to interpret the empirically perceived time relation by the correspond ing category [e. g. to apprehend regular succession as causality] ; transcendental philosophy, conversely, has to seek the justification
ideation, in which individual sensations may order
separate and unite in any way whatever, stands objective think ing, which is equally valid for all, and is bound to fixed, co herent, ordered wholes, in which the connections are governed by conceptions.
themselves,
up by
Chap. 1, J 38. ] Object of Knowledge : Experience. 545
of this procedure in the fact that the category, as a rule of the understanding, gives the corresponding time relations a rational basis as object of experience.
In fact, the individual consciousness finds in itself the contiast between a movement of ideas (say of the fancy), for which it claims no validity beyond its own sphere, and, on the other hand, an activ ity of experience, in the case of which it knows itself to be bound in a way that is likewise valid for all others. Only in this depend ence consists the reference of thought to an object. But if it was now recognised that the ground of the objective validity of the time (and space) relation can rest only in its determination by a rule of the understanding, it is on the other hand a fact that the consciousness of the individual knows nothing of this co-opera tion of the categories in experience, and that he rather accepts the
result of this co-operation as the objective necessity of his appre hension of the synthesis of sensations in space and time.
The production of the object, therefore, does not go on in the individual consciousness, but lies already at the basis of this con sciousness ; for this production, a higher common consciousness must therefore be assumed, which comes into the empirical consciousness of the individual, not with its functions, but only with their result. This Kant termed in the Prolegomena, consciousness in general; in the" Critique, transcendental appeixeption, or the "I" [or l'self" or ego"]. *
Experience is accordingly the system of phenomena in which the l spatial and temporal synthesis of sensation is determined by the rules \ of the understanding. Thus " Nature as phenomenon " is the object
of an a priori knowledge ; for the categories hold for all experience, ' / because experience is grounded only through them.
7. The universal and necessary force and validity of the cate gories find expression in the Principles of the Pure Understanding, in which the conceptional Forms unfold themselves through the medium of the schematism. But here it is at once evident that the main weight of the Kantian doctrine of the categories falls upon the third group, and thus upon those problems in which he hoped '•to solve Hume's doubt. " From the categories of Quantity and Quality result only the " Axiom of Perception," that all phenomena are extensive magnitudes, and the " Anticipations of Empirical Perception " according to which the object of sensation is an inten sive magnitude ; in the case of Modality there result only definitions of the possible, actual, and necessary, under the name of the '' Postu lates of Empirical Thought. " On the other hand, the Analogies of Experience prove that in Nature substance is permanent, and that
546 German Philosophy : Kant's Critique. [Past VL
its quantum can be neither increased nor diminished, that all changes take place according to the law of cause and effect, and that all substances are in thorough-going reciprocity or inter-action.
. These, therefore, are the universally and necessarily valid, prin-
/ciples and highest premises of all natural science, which are uni- / versally and necessarily valid without any empirical proof j they / contain what Kant calls the metaphysics of Nature. In order that they may be employed, however, upon the Nature given through
[
1 our senses, they must pass through a mathematical formulation,
I because Nature is the system of sensations perceived in the Forms
of space and time and ordered according to the categories. This transition is effected through the empirical conception of motion, to which all occurrence and change in Nature is theoretically to be reduced. At least, science of Nature, in the proper sense, reaches only so far as we can employ mathematics : hence Kant excluded psychology and chemistry from natural science as being merely descriptive disciplines. The "Metaphysical Elements of Natural Science " contain, accordingly, all that can be inferred universally and necessarily concerning the laws of motion, on the ground of the categories and of mathematics. The most important point in Kant's
philosophy of Nature, as thus built up, is his dynamic theory of mat ter, in which he now deduces from the general principles of the Critique the doctrine already laid down in the " Natural History of the Heavens," that the substance of that which is movable in space is the product of two forces which maintain an equilibrium in a
varying degree, — those of attraction and repulsion.
8. But in accordance with Kant's presuppositions, the above
metaphysics of Nature can be only a metaphysics of phenomena : and no other is possible, for the categories are Forms for relating, and as such are in themselves empty ; they can refer to an object only through the medium of perceptions, which present a manifold
content to be combined. This perception, however, in the case of us men, only the sensuous perception in the forms of space and time, and as content for their synthetic function we have only that given in sensations. Accordingly, the only object of human knowledge is experience, i. e. phenomenal appearance and the divis ion of objects of knowledge into phenomena and noumena, which has been usual since Plato, has no sense. A knowledge of things-in- themselves through " sheer reason," and extending beyond experi ence, nonentity, chimera.
But has, then, the conception of the thing-in-itself any rational meaning at all and not, together with this, the designation all objects of our knowledge as " phenomena," also without meaning?
|
?
a
a is
of
is a
;
is,
Chap. 1, §38. ] Object of Knowledge : Thing-in-Itsclf. 647
This question was the turning-point of Kant's reflections.
all that the naive conception of the world regards as " object " has been resolved partly into sensations, partly into synthetic Forms of perception and of the understanding; nothing seems to remain besides the individual consciousness as truly existing, except the
" consciousness in general," the transcendental apperception. But where, then, are the " things," of which Kant declared that it had never come into his mind to deny their reality ?
i l
The conception of the thing-in-itself can, to be sure, no longer have a positive content in the Critique of Reason, as it had with Leibniz, or in Kant's Inaugural Dissertation ; it can no longer be the object of purely rational knowledge, it can no longer be an "object" at all.
But it is at least no contradiction, merely to think it
purely hypothetically, and as something the reality of which is
neither to be affirmed nor to be denied, — a mere
Human knowledge is limited to objects of experience, because the perception required for the use of the categories is in our case only
< that there is another kind of ]>ercpption, there would be for this / /
other objects, likewise, with the help of the categories. Such objects of a non-human perception, however, remain still only phenomena, though this perception again might be assumed as one which arranges the given contents of sensation in any manner whatever.
Nevertheless, if one should think of a perception of a non-receptive kitid, a perception which synthetically produced not only its Forms, but also its contents, — a truly "productive imagination," — its objects would necessarily be no longer phenomena, but things-in- themselves. Such a faculty would deserve the name of an intellect ual perception (or intuition), or intuitive intellect; it would be the unity of the two knowing faculties of sensibility and understand ing, which in man appear separated, although by their constant reference to each other they indicate a hidden common root. The possibility of such a faculty is as little to be denied as its reality is to be affirmed ; yet Kant here indicates that we should have to think a supreme spiritual Being in this way. Noumena, or things- in-themselves, are therefore thinkable in the. negative tense as objects of a non-sensuous perception, of which, to be sure, our knowledge can predicate absolutely nothing, — they are thinkable as limiting con ceptions of experience.
And ultimately they do not remain so completely problematical| :i* would at first appear. For if we should deny the reality of things-in-themselves, "all would be immediately resolved into phenomena," and we should thus be venturing the assertion that
'
Hitherto
Primarily,
" problem. "
j
the receptive sensuous perception in space and time. If we suppose 1
^\
648 Oerman Philosophy : Kant* Critique. [Part VL
nothing is real except what appears to man, or to other sensuously receptive beings. But this assertion would be a presumption com pletely incapable of proof. Transcendental idealism must, therefore, not deny the reality of noumena; it must only remain conscious that they cannot in any wise become objects' of human knowledge. Things-in-themselves must be thought, but are not knowable. In this way Kant won back the right to designate the objects of human knowledge as "only phenomena. "
9. With this the way was marked out for the third part of the critique of the reason, the Transcendental Dialectic. 1 A metaphysics of that whioh cannot be experienced, or, as Kant prefers to say, of the supersensuous, is impossible. This must be shown by a criticism of the historical attempts which have been made with this in view, and Kant chose, as his actual example for this, the Leibnizo- Wolffian school-metaphysics, with its treatment of rational psychology, cos mology, and theology. But at the same time, it must be shown that that which is incapable of being experienced, which cannot be known, must yet necessarily be thought ; and the transcendental illusion must be discovered, by which even the great thinkers have at all times been seduced into regarding this, which must necessarily be thought, as an object of possible knowledge.
To attain this end Kant proceeds from the antithesis between the activity of the understanding and the sensuous perception by the aid of which alone the former produces objective knowledge. The thinking, which is determined by the categories, puts the data of the sensibility into relation with one another in such a way, that every phenomenon is conditioned by other phenomena : but in this process the understanding, in order to think the individual phenom enon completely, must needs grasp the totality of the conditions by which this particular phenomenon is determined in its connection* with the whole experience. But, in view of the endlessness of the world of phenomena in its relation to space and time, this demand cannot be fulfilled. For the categories are principles of relation between phenomena ; they cognise the eonditionality or conditional character of each phenomenon only by means of other phenomena, and demand for these again insight into their conditional nature as determined by others, and so on to infinity. ' Out of this relation
» As regards the subject matter, the Transcendental Esthetic Analytic, aai Dialetic. as the Introduction shows, form the three main co-ordinate para of the Critin** . ' the formal schematism of the dirision which Kant imitated froai the arrangement of logical text-books usual at that time, is, on the contrary. entirely irrelevant. The •' Doctrine of Method " is in fact only a supplement extremely rich in tine observations.
* Of. the similar thoughts in Xkolaus Cusanus and Spinoxa. though then metaphysically applied : above, pp. $47 and 419.
Ciiah. 1, § 38. ] Object of Knoicledye : Idea*. 649
between understanding and sensibility result for human knowledge necessary and yet insoluble problems; these Kant calls Ideas, and the faculty requisite for this highest synthesis of the cognitions of the understanding he designates as Reason in the narrower sense.
If now the reason will represent to itself as solved, a problem thus set, the sought totality of conditions must be thought as some l thing unconditioned, which, indeed, contains in itself the conditions
for the infinite series of phenomena, but which is itself no longer conditioned. This conclusion of an infinite series, which for the knowledge of the understanding is in itself a contradiction, must nevertheless be thought, if the task of the understanding, which L aims at totality in connection with the infinite material of the data
of the senses, is to be regarded as performed. The Ideas are hence ideas or mental representations of the unconditioned, which must necessarily be thought without ever becoming object of knowledge,
and the transcendental illusion into which metaphysics falls con sists in regarding them as given, whereas they are only imposed or
set as a task (aufgegeben). In truth they are not constitutive prin ciples through which, as through the categories, objects of knowl edge are produced, but only regulative principles, by which the understanding is constrained to seek for farther and farther con necting links in the realm of the conditioned of experience.
Of such Ideas Kant finds three ; the unconditioned for the totality of all phenomena of the inner sense, of all data of the outer sense, of all the conditioned in general, is thought respectively as the soul, the world, and Ood.
10. The criticism of rational psychology in the " Paralogisms of Pure Reason " takes the form of pointing out in the usual proofs for the substantiality of the soul, the quaternio terminorum of a confusion of the logical subject with the real substrate ; it shows that the scientific conception of substance is bound to our perception of that which persists in space, and that it is therefore applicable only in the field of the external sense, and maintains that the Idea of the soul as an unconditioned real uuity of all phenomena of the inner sense, is indeed as little capable of proof as it is of refutation, but is at the same time the heuristic principle for investigating the inter-connections of the psychical life. " "
In a similar way, the section on the Ideal of the Reason
treats the Idea of God. Carrying out with greater precision his earlier
treatise on the same subject, Kant destroys the cogency of the arguments brought forward for the existence of God. He combats the right of the ontological proof to infer existence from the concep-
650 German Philosophy : Kant'* Critique. [Part VL
tion alone ; he shows that the cosmological proof involves a petitio prindpii when it seeks the " first cause " of all that is "contingent " in an " absolutely necessary " being ; he proves that the teleological or physico-tAeological argument at the best — granted the beauty, harmony, and purposiveness or adaptation of the universe —leads to the ancient conception of a wise and good '* Architect of the world. " But he emphasises that the denial of God's existence is a
claim which steps beyond the bounds of our experiential knowledge, and is as incapable of proof as the opposite, and that rather the belief in a living, Real unity of all reality constitutes the only powerful motive for empirical investigation of individual groups of phenomena.
Most characteristic by far, however, is Kant's treatment of the Idea of the world in the Antinomies of Pure Reason.
