Kant's Refutation of Idealism

1. Philosophy 190: Seminar on Kant Spring, 2015 Prof. Peter Hadreas Course website: http://oucampus.sjsu.edu/people/peter.hadreas/courses/Kant/index.html

2. Analogies of Experience Postulates of Reason & Refutation of Idealism

4. Kant’s Refutation of Idealism CPR, pp. 326-329

5. Kant’s Refutation of Idealism The text CPR, pp. 326-329 “Idealism (I mean material idealism) is the theory that declares the existence of objects in space outside us to be either merely doubtful and indemonstrable, or else false and impossible; the former is the problematic idealism of Descartes, who declares only one empirical assertion (assertio), namely I am, to be indubitable; the latter is the dogmatic idealism of Berkeley, who declares space, together with all the things to which it is attached as an inseparable condition, to be something that is impossible in itself, and who therefore also declares things in space to be merely imaginary. Dogmatic idealism is unavoidable if one regards space as a property that is to pertain to the things in themselves; for then it, along with everything for which it serves as a condition, is a non-entity.”

6. Kant’s Refutation of Idealism The text CPR, pp. 326-329 “The ground for this idealism, however, has been undercut by us in the Transcendental Aesthetic. Problematic idealism, which does not assert anything about this, but rather professes only our incapacity for proving an existence outside us from our own by means of immediate experience, is rational and appropriate for a thorough philosophical manner of thought, allowing, namely, no decisive judgment until a sufficient proof has been found. The proof that is demanded must therefore establish that we have experience and not merely imagination of outer things, which cannot be accomplished unless one can prove that even our inner experience, undoubted by Descartes, is possible only under the presupposition of outer experience. “

7. Kant’s Refutation of Idealism The text CPR, pp. 326-329 Theorem “The mere, but empirically determined, consciousness of my own existence proves the existence of objects in space outside me.”

8. Kant’s Refutation of Idealism The text CPR, pp. 326-329 Proof ”I am conscious of my existence as determined in time. All time-determination presupposes something persistent in perception. This persistent thing, however, cannot be something in me, since my own existence in time can first be determined only through this persistent thing. Thus the perception of this persistent thing is possible only through a thing outside me and not through the mere representation of a thing outside me. Consequently, the determination of my existence in time is possible only by means of the existence of actual things that I perceive outside myself.”

9. Kant’s Refutation of Idealism The text CPR, pp. 326-329 Proof [continued from previous slide] “Now consciousness in time is necessarily combined with the consciousness of the possibility of this time-determination: Therefore it is also necessarily combined with the existence of the things outside me, as the condition of time-determination; i.e., the consciousness of my own existence is at the same time an immediate consciousness of the existence of other things outside me.”

10. Kant’s Refutation of Idealism The text CPR, pp. 326-329 Note 1. One will realize that in the preceding proof the game that idealism plays has with greater justice been turned against it. Idealism assumed that the only immediate experience is inner experience, and that from that outer things could only be inferred, but, as in any case in which one infers from given effects to determinate causes, only unreliably, since the cause of the representations that we perhaps falsely ascribe to outer things can also lie in us. Yet here it is proved that outer experience is really immediate, that only by means of it is possible not, to be sure,

11. Kant’s Refutation of Idealism: The text CPR, pp. 326-329 Note 1. [continued from previous slide] the consciousness of our own existence, but its determination in time, i.e., inner experience. Of course, the representation I am, which expresses the consciousness that can accompany all thinking, is that which immediately includes the existence of a subject in itself, but not yet any cognition of it, thus not empirical cognition, i.e., experience; for to that there belongs, besides the thought of something existing, intuition, and in this case inner intuition, i.e., time, in regard to which the subject must be determined, for which outer objects are absolutely requisite, so that and possible only through outer experience.

12. Kant’s Refutation of Idealism: The text CPR, pp. 326-329 Note 2. All use of our faculty of cognition in experience for the determination of time agrees with this completely. Not only can we perceive all time-determination only through the change in outer relations (motion) relative to that which persists in space (e.g., the motion of the sun with regard to the objects on the earth); we do not even have anything persistent on which we could base the concept of a substance, as intuition, except merely matter, and even this persistence is not drawn from outer experience, but rather presupposed a priori as the necessary condition of all time-determination, thus also as the determination of inner sense in regard to our own existence through the existence of outer things.

13. Kant’s Refutation of Idealism: The text CPR, pp. 326-329 Note 2. [continued from previous slide] The consciousness of myself in the representation I is no intuition at all, but a merely intellectual representation of the self activity of a thinking subject. And hence this I does not have the least predicate of intuition that, as persistent, could serve as the correlate for time-determination in inner sense, as, say, impenetrability in matter, as empirical intuition, does.

14. Kant’s Refutation of Idealism: The text CPR, pp. 326-329 Note 3. From the fact that the existence of outer objects is required for the possibility of a determinate consciousness of our self it does not follow that every intuitive representation of outer things includes at the same time their existence, for that may well be the mere effect of the imagination (in dreams as well as in delusions); but this is possible merely through the reproduction of previous outer perceptions, which, as has been shown, are possible only through the actuality of outer objects. Here it had to be proved only that inner experience in general is possible only through outer experience in general. Whether this or that putative experience is not mere imagination must be ascertained according to its particular determinations and through its coherence with the criteria of all actual experience.

15. William James on Sense of Self and External World. "In a sense, then, it may be truly said that, in one person at least, the "Self of selves," when carefully examined, is found to consist mainly of the collection of these peculiar motions in the head or between the head and throat. I do not for a moment say that this is all it consists of, for I fully realize how desperately hard is introspection in this field. But I feel quite sure that these cephalic motions are the portions of my innermost activity of which I am most distinctly aware. If the dim portions which I cannot yet define should prove to be like unto these distinct portions in me, and I like other men, it would follow that our entire feeling of spiritual activity, or what commonly passes by that name, is really a feeling of bodily activities whose exact nature is by most men overlooked.”1 1. William James writes in Principles of Psychology, in Great Books of the Western World, Vol. 53, (Chicago: Encyclopedia Britannica, Inc., 1952), p. 193-4.

16. Wittgenstein on Sense of Self in Another’s Body "If we had a sensation of toothache plus certain tactual and kinaesthetic sensations usually characteristic of touching the painful tooth and neighboring part of our face, and if these sensations were accompanied by seeing my hand touch, and move about on, the edge of my table, we should feel doubtful whether to call this experience an experience of toothache in the table or not. If, on the other hand, the tactual and kinesthetic sensations described were correlated to the visual experience of seeing my hand touch a tooth and other parts of the face of another person, there is no doubt that I would call this experience "toothache in another person's tooth".1 1. Ludwig Wittgenstein writes in the Blue Book: Wittgenstein, Ludwig, The Blue and Brown Books, (New York: Harper Colophon Books, 1958), p. 50:

17. Kant on ‘The Analogies of Experience’

18. The Truth of Time and Space in Popular Culture The eight-year-old Master (William Hughes) stares into the Untempered Schism In the sci-fi series Doctor Who an evil villain known only as ‘The Master’ is placed in front of the temporal schism. He sees time for what it is loses his mind and plots against creation. In "The Sound of Drums" (2007) and The End of Time (2009–2010), a flashback shows the Master at the age of eight, during a Time Lord initiation ceremony where he is taken before a gap in the fabric of space and time known as the Untempered Schism, from which one can see into the entire Vortex. The Doctor states that looking into the time vortex causes some Time Lords to go mad. 1 1. Adapted from text at http://en.wikipedia.org/wiki/Master_%28Doctor_Who%29

19. Analogies of Experience The three analogies correspond to the three modes of time:

20. First Analogy of Experience: Principle of the Persistence of Substance “Only through that which persists does existence in different parts of the temporal series acquire a magnitude, which one calls duration. For in mere sequence alone existence is always disappearing and beginning, and never has the least magnitude. Without that which persists there is therefore no temporal relation. Now time cannot be perceived in itself; thus this persisting thing in the appearances is the substratum of all time-determination, consequently also the condition of the possibility of all synthetic unity of perceptions, i.e., of experience, and in this persisting thing all existence and all change in time can only be regarded as a modus of the existence of that which lasts and persists.” (p. 301) [continues]

21. First Analogy of Experience: Principle of the Persistence of Substance [continued from previous slide] “Therefore in all appearances that which persists is the object itself, i.e., the substance (phaenomenon), but everything that changes or that can change belongs only to the way in which this substance or substances exists, thus to their determinations.” (p. 301)

22. Second Analogy. Principle of temporal sequence according to the law of causality.

23. Second Analogy of Experience: Temporal Sequence According the law of causality “Thus, e.g., the apprehension of the manifold in the appearance of a house that stands before me is successive. Now the question is whether the manifold of this house itself is also successive, which certainly no one will concede. Now, however, as soon as I raise my concept of an object to transcendental significance, the house is not a thing in itself at all but only an appearance, i.e., a representation, the transcendental object of which is unknown; therefore what do I understand by the question, how the manifold may be combined in the appearance itself (which is yet nothing in itself)?” (p. 306)

24. Second Analogy of Experience: Causal Succession “Since this is the case in all synthesis of apprehension, however, as I have shown above in the case of the appearance of a house, the apprehension of an occurrence is not yet thereby distinguished from any other. Yet I also note that, if in the case of an appearance that contains a happening I call the preceding state of perception A and the following one B, then can only follow A in apprehension, but the perception A cannot follow but only precede B. E.g., I see a ship driven downstream. My perception of its position downstream follows the perception of its position upstream, and it is impossible that in the apprehension of this appearance the ship should first be perceived downstream and afterwards upstream.” (pp. 306-7) [continues]

25. Second Analogy of Experience: Temporal Sequence According the law of causality [continued from previous slide] . . . “The order in the sequence of the perceptions in apprehension is therefore here determined, and the apprehension is bound to it. In the previous example of a house my perceptions could have begun at its rooftop and ended at the ground, but could also have begun below and ended above; likewise I could have apprehended the manifold of empirical intuition from the right or from the left. In the series of these perceptions there was therefore no determinate order that made it necessary when I had to begin in the apprehension in order to combine the manifold empirically. But this rule is always to be found in the perception of that which happens, and it makes the order of perceptions that follow one another (in the apprehension of this appearance) necessary.” (pp. 306-7)

26. Second Analogy of Experience: Temporal Sequence According the law of causality “This causality leads to the concept of action, this to the concept of force, and thereby to the concept of substance. Since I will not crowd my critical project, which concerns solely the sources of synthetic a priori cognition, with analyses that address merely the elucidation (not the amplification) of concepts, I leave the detailed discussion of these concepts to a future system of pure reason -especially since one can already find such an analysis in rich measure even in the familiar textbooks of this sort. Yet I cannot leave untouched the empirical criterion of a substance, insofar as it seems to manifest itself better and more readily through action than through the persistence of the appearance.” (p. 313)

27. Third Analogy. Principle of simultaneity, according to the law of interaction, or community.

28. Third Analogy. Principle of simultaneity, according to the law of interaction, or community. “Things are simultaneous if in empirical intuition the perception of one can follow the perception of the other reciprocally (which in the temporal sequence of appearances, as has been shown in the case of the second principle, cannot happen). Thus I can direct my perception first to the moon and subsequently to the earth, or, conversely, first to the earth and then subsequently to the moon, and on this account, since the perceptions of these objects can follow each other reciprocally, I say that they exist simultaneously.” (p. 316)

29. Third Analogy. Principle of simultaneity, according to the law of interaction, or community. “Things are simultaneous insofar as they exist at one and the same time. But how does one cognize that they exist at one and the same time? If the order in the synthesis of the apprehension of this manifold is indifferent, i.e., if it can proceed from A through B, C, and D to E, but also conversely from E to A. For if they existed in time one after the other (in the order that begins with A and ends at E), then it would be impossible to begin the apprehension at the perception of E and proceed backwards to A, since A would belong to past time, and thus can no longer be an object of apprehension.” (p. 317)

30. Heidegger: Kant and Problem of Metaphysics “Because of his orientation on the non-original essence of time, Kant is forced to deny all temporal character to ‘the principle of contradiction.’ It would be contrary to sense to try to effect an essential determination of primordial time itself with the aid of what is derived from it. The ego cannot be conceived as temporal, i. e., intra-temporal, precisely because the self originally and in its innermost essence is time itself. Pure sensibility (time) and pure reason are not only homogeneous, they belong together in the unity of the same essence which makes possible the finitude of human subjectivity in its totality.”1 1. Heidegger, Martin, Kant and the Problem of Metaphysics, trans. Churchill, (Bloomington, IN: Indiana University Press, 1962), p. 200-1

31. Heidegger: Kant and the Problem of Metaphysics1 Martin Heidegger (1889 –1976) 1. Heidegger, Martin, Kant and the Problem of Metaphysics, trans. Churchill, (Bloomington, IN: Indiana University Press, 1962), p. 200-1

32. Heidegger: Kant and Problem of Metaphysics “It is at once obvious, therefore, that time as pure self-affection is not found ‘in the mind’‘beside’ pure apperception. On the contrary, as the basis of the possibility of selfhood, time is already included in pure apperception and first enables the mind to be what it is. “The pure finite self has in itself a temporal character. Therefore, if the ego, i.e., pure reason, is essentially temporal, the fundamental determination which Kant provides for transcendental apperception must first become intelligible through this temporal character.”1 1. Heidegger, Martin, Kant and the Problem of Metaphysics, trans. Churchill, (Bloomington, IN: Indiana University Press, 1962), p. 197

33. Heidegger: Kant and Problem of Metaphysics “Time and the ‘I think’ are no longer opposed to one another as unlike and incompatible; they are the same. Thanks to the radicalism with which, in the laying of the foundation of metaphysics, Kant for the first time subjected time and the ‘I think,’ each taken separately, to a transcendental interpretation, he succeeded in bringing them together in their primordial identity — without, to be sure, having seen this identity expressly as such.” 1. Heidegger, Martin, Kant and the Problem of Metaphysics, trans. Churchill, (Bloomington, IN: Indiana University Press, 1962), p. 200-1

34. Heidegger: Kant and Problem of Metaphysics “Can one still consider it to be of no importance that in speaking of time and the ‘I think,’ Kant used the same essential predicates?  In the transcendental deduction, the transcendental nature (i.e., that which makes transcendence possible) of the ego is thus described: ‘The abiding and unchanging 'I' (pure apperception) forms the correlate of all our representations.’ And in the chapter on schematism wherein the transcendental essence of time is brought to light, Kant says: ‘The existence of what is transitory passes away in time but not time itself.’ And further on: ‘Time . . . does not change.’ 1. Heidegger, Martin, Kant and the Problem of Metaphysics, trans. Churchill, (Bloomington, IN: Indiana University Press, 1962), p. 197.

35. Heidegger: Kant and Problem of Metaphysics “Naturally, it could be objected that this coincidence of essential predicates is not surprising, for Kant in making use of this terminology intends only to assert that neither the ego nor time is ‘in time.’ Certainly, but does it follow from this that the ego is not temporal? Rather, is it not necessary to conclude that the ego is so temporal that it is time itself and that only as such in its very essence is it possible at all?” 1. Heidegger, Martin, Kant and the Problem of Metaphysics, trans. Churchill, (Bloomington, IN: Indiana University Press, 1962), pp. 197-8.

36. Heidegger: Kant and Problem of Metaphysics “What does it mean to say that the "abiding and unchanging 'I' forms the correlate of all our representations"? First of all, that the "abiding and unchanging" ego carries out the act of ob-jectification, which act forms not only the relation of from-the-self-toward . . . [Hin-zu-auf . . . ], but also the correlation of back-to [the self], and as such constitutes the possibility of opposition. But why does Kant assert that the "abiding and unchanging" ego accomplishes [bilde] this act of ob-jectification? 1. Heidegger, Martin, Kant and the Problem of Metaphysics, trans. Churchill, (Bloomington, IN: Indiana University Press, 1962), p. 198.

37. Heidegger: Kant and Problem of Metaphysics “Does he mean to emphasize that the ego is always found at the basis of all mental events and "persists" as something unaffected by the vicissitudes which characterize such events? . . . But why does this supposed affirmation appear precisely where it does — there where Kant delimits the finitude of the ego, i.e., its act of ob-jectification? For the simple reason that the permanence and immutability of the ego belong essentially to this act. 1. Heidegger, Martin, Kant and the Problem of Metaphysics, trans. Churchill, (Bloomington, IN: Indiana University Press, 1962), p. 198

38. Heidegger: Kant and Problem of Metaphysics “The predicates "abiding" and "unchanging" are not ontic assertions concerning the immutability of the ego but are transcendental determinations. They signify that the ego is able to form an horizon of identity only insofar as qua ego it pro-poses to itself in advance something on the order of permanence and immutability. It is only within this horizon that an object is capable of being experienced as remaining the same through change. The "abiding" ego is so called because as the "I think," i.e., the "I represent," it pro-poses to itself the like of subsistence and persistence. Qua ego, it forms the correlative of subsistence in general.” The provision of a pure aspect of the present in general is the very essence of time as pure intuition. The description of the ego as "abiding and unchanging" means that the ego in forming time originally, i.e., as primordial time, constitutes the essence of the act of ob-jectification and the horizon thereof. Nothing has been decided, therefore, concerning the atemporality and eternity of the ego. Indeed, the transcendental problematic in general does not even raise this question. It is only as a finite self, i.e., as long as it is temporal, that the ego is "abiding and unchanging" in the transcendental sense. A 123, NKS, p. 146. A 143, B 183, NKS, p. 184. A 182, B 225, NKS, p. 213. A 348ff., B 406ff., NKS, p. 333ff. 1 1. Heidegger, Martin, Kant and the Problem of Metaphysics, trans. Churchill, (Bloomington, IN: Indiana University Press, 1962), p. 200-1

39. Heidegger: Kant and Problem of Metaphysics “ The provision of a pure aspect of the present in general is the very essence of time as pure intuition. The description of the ego as "abiding and unchanging" means that the ego in forming time originally, i.e., as primordial time, constitutes the essence of the act of ob-jectification and the horizon thereof.  Nothing has been decided, therefore, concerning the atemporality and eternity of the ego. Indeed, the transcendental problematic in general does not even raise this question. It is only as a finite self, i.e., as long as it is temporal, that the ego is "abiding and unchanging" in the transcendental sense.1 1. Heidegger, Martin, Kant and the Problem of Metaphysics, trans. Churchill, (Bloomington, IN: Indiana University Press, 1962), p. 199

40. Slides #1 and following, Portrait of Immanuel Kant in mid-life: http://www.lancaster.ac.uk/users/philosophy/courses/100/Kant003.jpg