1 There are of course other more recent philosophers who offer Kantian alternatives to foundationalism- among whom the most prominent is Wilfrid Sellars -although not necessarily by adopting the view that there are fixed elements in the structure of knowledge which play a constitutive role.

2 In this paper, following Kant, I use ‘a priori’ as a modifier of ‘knowledge’ or of ingredients of knowledge. Thus in talking about Descartes’s a priori I mean Descartes’s notion of knowledge (cognitio or scientia) independent of experience or the intellectual ideas involved in such knowledge. As far as I have been able to determine, Descartes does not use ‘a priori’ in this Kantian way. Moreover, on the occasion when Descartes uses it to modify ‘method of proof,’ by the end of the Second Replies, he does not mean a method independent of the senses, but rather a method that proceeds, as he puts it, ‘from causes to effects.’ Descartes is characterizing there- following the medieval and seventeenth century usage of ‘a priori’- the analytic method employed in the Meditations on First Philosophy. See Reply to Objections II in The Philosophical Works of Descartes, trans. Haldane, Elizabeth S. and Ross, G.R.T. (Cambridge: Cambridge University Press 1967) II, 48.Google Scholar All references to Descartes’s works will be from this two volume translation, to be abbreviated as ‘HR,’ and from Descartes: Philosophical Letters, trans. Kenny, Anthony (Minneapolis: University of Minnesota Press 1981)Google Scholar, to be abbreviated as ‘K.’ For a reference to Descartes’s adoption of the medieval and seventeenth-century usage of ‘a priori,’ see Alquie’s, annotation to his edition of the reply in Descartes, Oeuvres philosophiques, Alquie, F. ed. (Paris: Garnier 1967), II, 581-5.Google Scholar I owe this last reference to Edwin Curley.

3 That Descartes puts epistemology at the center of philosophy is a widely accepted but not uncontroversial point. Wilson, Margaret for example, in her book Descartes (London, Henley, and Boston: Routledge and Kegan Paul 1978)Google Scholar argues that to hold that Descartes accords epistemological questions priority over questions about the nature of reality is misleading. However, by ‘epistemological questions or issues’ she seems to have in mind mainly Cartesian doubt and the problem of skepticism. She seems to think, in addition, that, because many of Descartes’s epistemological views are undeveloped or lack complexity, he does not give priority to epistemology. In this paper I will not assess the intrinsic value, sophistication or complexity of specific epistemological doctrines of Descartes. Nor will I try to answer Wilson on this point. Here I can only assert without argument that regardless of how limited Descartes’s epistemological views are, especially in comparison with Kant’s, I still believe that Descartes puts epistemology at the center of philosophy -particularly in his most widely read work, the Meditations. As it will become clearer below, my conviction is for the most part based on the method followed in the Meditations. This is a method conceived in essential dependence of the limitations of human understanding and of the fact of human knowledge.

4 The minimum common ground of adopting the human rational point of view, and of giving a central role to the ‘I think’ has led to Kantian interpretations of Descartes, such as Gueroult, Martial’s interpretation of the Cogito in his Descartes’ Philosophy Interpreted According to the Order of Reasons, trans. Ariew, Roger (Minneapolis: University of Minnesota Press 1984)Google Scholar, and to Cartesian interpretations of the Kantian transcendental unity of apperception. I reject these interpretations, but I will not offer a full discussion of them here. My main reason for rejecting such interpretations is my conviction that we must understand the two above-mentioned features of Kant’s philosophy in connection with Kant’s transcendental idealism. This form of idealism is opposed to the transcendental realism of Descartes. It is also opposed to the other side of Descartes’s transcendental realism, namely Descartes’s empirical psychologism. For English language interpretations of Kant which emphasize the centrality of transcendental idealism in Kant’s philosophy, see Bird, GrahamKant’s Theory of Knowledge (New York: Humanities Press 1962);Google Scholar and Allison, HenryKant’s Transcendental Idealism (New Haven and London: Yale University Press 1983).Google Scholar

5 This is the reality simpliciter - being or perfection - that entities (including ideas) have, as opposed to the objective reality that only ideas can possess precisely in virtue of being entities that represent something or other. Different entities have different degrees of formal reality: substances have more formal reality than accidents or modes; and the infinite substance has more than finite substances. Ideas can have more or less objective reality depending on the formal reality of what they represent. See, for example, Third Meditation, HR I, 162, and Second Replies, HR II, 56.

6 In my ‘Subjective Justification,’ Canadian Journal of Philosophy 19 (1989) 363-82CrossRefGoogle Scholar, I draw the contrast between ‘subjective’ and ‘objective’ justification: between psychological-epistemological reasons that a person might possess for believing something and logical reasons that objectively provide grounding for propositions independently of the empirical ways in which believers might establish connections among them. I believe this distinction overlaps in general terms with Descartes’s distinction between analytic and synthetic methods. Martial Gueroult, in characterizing the two methods (I, 9), seems to have in mind something very similar to the distinction between subjective and objective justification in my sense. For a recent detailed discussion of the analytic method in the Meditations, see Curley, Edwin ‘Analysis in the Meditations: The Quest for Clear and Distinct Ideas’ in Essays on Descartes’ Meditations, Oksenberg Rorty, Amelie ed. (Berkeley and Los Angeles: University of California Press 1986), 153-76.Google Scholar Curley takes the main distinguishing trait of the analytic method to be its non-deductive character, as opposed to the deductive character of the synthetic method. His description of the non-deductive procedure emphasizes specific ways - such as the introduction of concepts by means of examples, or the ‘dialectical method’ -by which Descartes attempts to guide any of us, who are attached to the senses and proceed according to common sense, to arrive at the clear and distinct perception of the first principles. Leaving aside the details of Curley’s account, his understanding of the analytic method does not seem inconsistent with the broad features of my way of presenting the method here.

7 All references to the Critique of Pure Reason are from Norman Kemp Smith’s translation: Immanuel Kant’s Critique of Pure Reason (New York: St. Martin’s Press 1965), and to the standard numbering of the A (first) or B (second) German editions.

8 See A 50-62/B 74-86; A 67-83/B 92-109.

9 Kant says: ‘Certainly, the representation “I am,” which expresses the consciousness that can accompany all thought, immediately includes in itself the existence of a subject; but it does not so include any knowledge of that subject, and therefore also no empirical knowledge, that is, no experience of it’ (B 277).

10 See A 106-8, and B 131-40 (sections 16-18 of the Transcendental Deduction of the Pure Concepts of the Understanding in the B edition).

11 See The Paralogisms of Pure Reason: A 341-8/B 399-406; A 349-405; B 407-32. For a very original and thorough discussion of Kant’s philosophy of mind, see Ameriks, KarlKant’s Theory of Mind: An Analysis of the Paralogisms of Pure Reason (Oxford: Clarendon Press 1982).Google Scholar For another helpful, although much briefer, English language commentary on this topic, see Henry Allison, ch. 13. I am not suggesting that either of these Kant scholars would agree with the sentences preceding this note. For an exposition from a Descartes scholar who seems to disagree with the contrast I am making between Descartes and Kant on the transcendental self, see Martial Gueroult, I, ch. 3-4. In these chapters Gueroult gives a Kantian-transcendental interpretation of the Cartesian Cogito.

12 This part of the Critique is Kant’s answer to skepticism regarding the possibility of knowledge of things in space. Descartes’s ‘problematic idealism’ denies that we can have immediate experience and thus certainty with respect to the existence of objects outside our minds. For Kant we have immediate knowledge of objects in space, since space is an a priori intuition that makes it possible that there be an object of knowledge for us in the first place. Kant’s solution to the problem raised by ‘problematic idealism’ involves turning the Cartesian argument of the First and Second Meditations against Descartes by establishing a necessary connection between empirical self-consciousness - Descartes’s Cogito- and immediate experience of objects in space (see B 274-9).

13 See, e.g., B 72, and B 139. This clarification was prompted by the comments of an anonymous referee.

14 For a discussion of the discursive character of human understanding in contrast to the intuitive character of God’s intellect, see Kant’s Critique of Judgment, sec. 77.

15 In order for an a priori concept to acquire or to be applied to a content (to have an object), a mediating a priori intuitional third element is needed. See the First Critique, chapter on The Schematism of the Pure Concepts of Understanding, A 173/B 176 ff.

16 In the Metaphysical Deduction Kant says: ‘Thus in the judgment, “all bodies are divisible,” the concept of the divisible applies to various other concepts, but is here applied in particular to the concept of body, and this concept again to certain appearances that present themselves to us. These objects, therefore, are mediately represented through the concept of divisibility. Accordingly, all judgments are functions of unity among our representations, instead of an immediate representation, a higher representation, which comprises the immediate representation and various others, is used in knowing the object, and thereby much possible knowledge is collected into one’ (A 69 /B 93-4).

17 Kantian ‘judgments’ would roughly correspond- without the complexities associated with Kant’s doctrine of judgment- to Cartesian ideas when understood as propositions. But ‘judgment’ in Kant can also be understood as the act of judging, and thus it can also correspond to Cartesian perception of ideas. What Descartes calls ‘judgment’ is the act of assenting to or dissenting from, affirming or denying, ideas apprehended by the understanding, and does not belong to the faculty of understanding but to the faculty of choice or free will. (See Fourth Meditation, HR I, 171-9.) Therefore, whereas clear and distinct perception belongs to the understanding, apprehension of ideas (propositions) as true must be an act of the will. For difficulties associated with these doctrines see the works cited below in note 20.

18 For Descartes’s hostility towards logic, see Curley, EdwinDescartes Against the Skeptics (Cambridge, MA: Harvard University Press 1978), 25-34.CrossRefGoogle Scholar For the same topic, and a discussion of the contrast between Descartes and Leibniz regarding their differing conceptions of proof, see Hacking, Ian ‘Proof and Eternal Truths: Descartes and Leibniz,’ in Descartes: Philosophy, Mathematics and Physics, Gaukroger, Stephen ed. (Sussex: The Harvester Press 1980), 169-80.Google Scholar Hacking argues, among other points, that the Cartesian independence of truth from proof is illustrated by Descartes’s doctrine that the eternal truths depend on God’s will. For Leibniz and for us, as Hacking rightly points out, if a complete set of Euclidean axioms is true, then necessarily the Pythagorean theorem is true too. But for Descartes, God is at liberty to create a Euclidean but non-Pythagorean universe.

19 In my ‘Kant and Innatism,’ Pacific Philosophical Quarterly 68 (1987) 285-305, I discuss the connection between Kant’s stand against innatism and his transcendental and anti-psychologistic views. There I argue for the view that to make a priori knowledge rest on innate ideas amounts in the end to psychologism.

20 Some illuminating discussions of the difficulties of Descartes’s views on ‘ideas/ thoughts, consciousness, perception with the mind’s eye, judgment, and so on, are, for instance, Curley, Edwin ‘Descartes, Spinoza, and the Ethics of Belief’ in Spinoza, Essays in Interpretation, Mandelbaum, M. and Freeman, E. eds. (La Salle, IL: Open Court 1975), 159-89;Google ScholarKenny, AnthonyDescartes: A Study of his Philosophy (New York: Random House 1968)Google Scholar, ch. 5; Margaret Wilson, ch. 4.

21 I am aware that my interpretation of Descartes here is insufficiently developed and prima facie controversial; however, this is not the place to defend it. The issues involved are directly relevant to the topic of the Cartesian Circle. All of the secondary sources on Descartes mentioned in this paper have interesting albeit different interpretations of Descartes’s solution to the problem of the Circle.

22 Reality for Descartes should not be equated with existence. Thus in the Fifth Meditation, Descartes says: ‘I discover in myself an infinitude of ideas of certain things which cannot be esteemed as pure negations, although they may possibly have no existence outside of my thought, and which are not framed by me, although it is within my power either to think or not to think them, but which possess natures which are true and immutable. For example, when I imagine a triangle, although there may nowhere in the world be such a figure outside my thought, or ever have been, there is nevertheless in this figure a certain determinate nature, form, or essence, which is immutable and eternal, which I have not invented, and which in no wise depends on my mind, as appears from the fact that diverse properties of that triangle can be demonstrated …’ (HR I, 179-80). The proof of the existence of God in this Meditation depends on the possibility of this and related distinctions.

23 Notice that here, when talking about Kant’s doctrines, unlike when I describe Descartes’s views, I speak of the ‘possibility’ of truth, rather than of truth simpliciter. The reason for this qualification will become clearer below.

24 Gerd Buchdahl, for example, appealing to the Principles, among other texts, points out that physical assumptions enter crucially into Descartes’s scientific method, and that according to Descartes we are free to frame any physical assumptions provided that their deduced consequences agree with observations. See Buchdahl, G.Metaphysics and the Philosophy of Science (Oxford: Basil Blackwell 1969), 79-154.Google Scholar

25 I argue for this point in my ‘Kant and Innatism,’ of which this present paper can be regarded as a development and qualification. In particular I here attempt further to clarify Kant’s claim that a priori knowledge arises absolutely independently of experience.

26 Empiricists, such as Hume, share with Kant and Descartes the general characterization of a priori knowledge as knowledge justified or grounded independently of sensations (impressions for Hume). The notion of justification or grounding, as opposed to origin or formation of an idea, must be what Hume has in mind when he draws the distinction between reasoning on the basis of ’relations of ideas’ alone, and on the basis of ‘matters of fact.’ (See Hume, D.Enquiry Concerning Human Understanding (Oxford: Oxford University Press 1975)Google Scholar sec. IV, part I.) Otherwise he could not hold consistently both this distinction and his basic tenet that all ideas are ultimately originated in impressions. Hume can also be interpreted as sharing with Descartes the view that a priori knowledge (’relations of ideas’) is entirely independent of sensation, as opposed to the view that there is a reciprocal relation as the one discussed here. This unlikely alliance between Descartes and Hume and other empiricists is due to the fact that all of them are pre-Kantian. Of course empiricists do not share with Descartes the view that ideas of the understanding are independent of sensation with respect to their origin, and do not share the rationalist claim that we can have a priori knowledge of the physical world. The empiricist attack on the latter consists in an attack on innate ideas; therefore, it does not affect Kant’s views.

27 The Copernican revolution is announced in the Preface to the second edition of the Critique at B xvi, which explicitly links the Copernican revolution with the explanation of a priori knowledge. Other brief presentations of the main point of the Copernican revolution are, for example, at A 114, A 128-9, and B 166-7.

28 For other passages that make the same point, see for example the beginning of the chapter on Phenomena and Noumena at B 298/ A 239 ff., or the Schematism at B 178/ A 139, B 185/ A 146, or at B 186/ A 147. In these passages Kant is explicit not only about the fact that the a priori does not amount to knowledge if it is not applicable to empirical intuition, but also about the fact that it lacks meaning or content if it is not so applicable.

29 The negative claim against traditional rationalism has in turn a double aspect as it applies to philosophy and to non-philosophical knowledge. Speculative a priori metaphysics which seeks to know an unknowable realm should be replaced by an a priori metaphysics that concerns itself with the conditions of knowledge of appearance, of things as we experience them. In addition, nonphilosophical a priori knowledge, such as mathematics, amounts strictly speaking to knowledge only if it is applicable to experience.

30 One central aspect of Kant’s revolution of the a priori is the introduction- in addition to the a priori concepts of the understanding - of necessary a priori ingredients of experience that are intuitional. Understanding and intuition are two separate faculties, and to the extent that each provides separately a priori necessary elements of knowledge they are in a certain sense independent. Yet the pure a priori concepts of the understanding and the pure a priori forms of intuition are ultimately not independent from each other in knowledge, since the categories must be schematized - subsumed under space and time - in order for the principles of the understanding associated with them to be applicable to an empirical content, and thus to amount to knowledge.

31 See for instance Sosa, Ernest ‘The Raft and the Pyramid: Coherence versus Foundations in the Theory of Knowledge’ in Midwest Studies in Philosophy V: Studies in Epistemology, French, Peter A. et al;., eds. (Minneapolis: University of Minnesota Press 1980), 4-5.Google Scholar

32 Roderick Chisholm can be regarded as the contemporary English language paradigm of empiricist foundationalism. See, for example, his Theory of Knowledge (Englewood Cliffs, NJ: Prentice-Hall 1977).

33 See Rules I-VI, HR I, 1-19. The emphasis on the simplicity of the foundational truths is a peculiarity of Descartes, not to be found in most other foundationalist views. Gueroult places a great deal of importance on the simple character of the nature of the Cogito in the Meditations. See Gueroult, I, ch. 3. The simplicity of foundational truths should be contrasted with the complexity of Kant’s judgments discussed above.

34 Thus in a letter to Mersenne of 28 January 1641, Descartes says that the six Meditations contain all the foundations of his Physics, K, 94; in the introduction to the French translation of the Principles he says that: ‘philosophy as a whole is like a tree whose roots are metaphysics, whose trunk is physics, and whose branches, which issue from this trunk, are all the other sciences’ (HR I, 211).

35 Clearly, for scientific method this picture amounts to an oversimplification. As I pointed out above, Gerd Buchdahl and other commentators point to the empirical elements in Descartes’s derivation of physics. Furthermore, the tension in Descartes’s conception of his scientific method between the use of the hypothetical- deductive method and deduction can undermine the certainty of science. See G. Buchdahl, 118-55.

36 In the Third Meditation at HR I, 160-5; in Principle XI at HR I, 223; and so on.

37 ‘I bid them carefully rehearse those propositions, intelligible per se, which they find they possess, e.g., that the same thing cannot at the same time both be and not be; that nothing cannot be the efficient cause of anything, and so forth; and thus employ in its purity, and in freedom from the interference of the senses, that clarity of understanding that nature has implanted in them, but which sensuous objects are wont to disturb and obscure. For by this means the truth of the following Axioms will easily become evident to them’ (HR II, 54); ‘Among other things they must reflect that while possible existence indeed attaches to the ideas of all other natures, in the case of the idea of God that existence is not possible but wholly necessary. For from this alone and without any train of reasoning they will learn that God exists, and it will be not less self evident to them than the fact that number two is even and number three odd, and similar truths’ (HR II, 55). For an interesting discussion of Descartes’s use of these notions, see Anthony Kenny, ch. 8.

38 Compare my use of ‘evident’ with Bernard Williams’s use of this word and others such as ‘self-verifying,’ ‘incorrigible,’ ‘pragmatically self-defeating’ and so on, in Williams, B.Descartes: The Project of Pure Enquiry (New York: Viking Penguin 1978), 72-88.Google Scholar In this work Williams gives the following definition: ‘that a proposition is evident (with respect to A) means that if it is true, then A believes it’ (77). I am using ‘evident’ in a more standard way.

39 For an explanation of the notion of construction in pure intuition and of its central role in Kant’s conception of geometry, see Friedman, Michael ‘Kant’s Theory of Geometry,’ The Philosophical Review 44 (1985) 455-506.CrossRefGoogle Scholar

40 Thus Kant says: ‘There is indeed a transcendental synthesis [framed] from concepts alone, a synthesis with which the philosopher is alone competent to deal; but it relates only to a thing in general, as defining the conditions under which the perception of it can belong to possible experience’ (A 719 /B 747).

41 ‘A transcendental proposition is therefore synthetic knowledge through reason, in accordance with mere concepts; and it is discursive, in that while it is what alone makes possible any synthetic unity of empirical knowledge, it yet gives us no intuition a priori’ (A 722/B 750). Here Kant means by ‘transcendental proposition’ a proposition of philosophy.

42 ‘Now one concept cannot be combined with another synthetically and also at the same time immediately, since, to be able to pass beyond either concept, a third something is required to mediate our knowledge. Accordingly, since philosophy is simply what reason knows by means of concepts, no principle deserving the name of an axiom is to be found in it…. But a synthetic principle derived from concepts alone can never be immediately certain, for instance, the proposition that everything which happens has a cause. Here I must look round for a third something, namely, the condition of time-determination in an experience; I cannot obtain knowledge of such a principle directly and immediately from the concepts alone. Discursive principles are therefore quite different from intuitive principles, that is, from axioms; and always require a deduction. Axioms, on the other hand, require no such deduction, and for the same reason are evident - a claim which the philosophical principles can never advance, however great their certainty. Consequently, the synthetic propositions of pure, transcendental reason are, one and all,infinitely removed from being as evident … as the proposition that twice two make four’ (A 732-3/B 760-1).

43 In the Critique, in the section on the Postulates of Empirical Thought, Kant gives as the first postulate: ‘1. That which agrees with the formal conditions of experience, that is, with the conditions of intuition and of concepts, is possible’ (A 218/B 265).

44 As I suggested earlier, there is a strong claim involved in the proof: not only are the categories (and a priori intuitions) necessary conditions for us to experience (represent) things the way we do, but they are necessary conditions for there being an objective world distinct from our contingent ways of representing it. The stronger claim, or more specifically our knowledge that the stronger claim is true, is the only one suitable for an answer to skepticism. Stroud, Barry in his ’Transcendental Arguments,’ reprinted in Kant on Pure Reason, Walker, Ralph ed. (Oxford: Oxford University Press 1982) 117-31Google Scholar, makes a similar point regarding the strength required of transcendental arguments if they are to succeed in answering the skeptic. Stroud argues that recent attempts to use transcendental arguments to answer skepticism rely on the verification principle. Although he does not say it explicitly, he seems to suggest that Kant’s argument also relies on the verification principle. I believe Kant’s argument does not need to rely on such a principle, but this is not the place to argue for this view.

45 For details on how the Meditations might relate to the foundations of Cartesian physics, see E. Curley, ch. 8; for the role of God in the derivation of the laws of motion, see Gueroult, M. ‘The Metaphysics and Physics of Force in Descartes,’ in Gaukroger, Stephen ed., 196-229.Google Scholar

46 Dieter Henrich has shown this in ‘Kant’s Notion of a Deduction and the Methodological Background of the First Critique,’ in Kant’s Transcendental Deductions: The Three ‘Critiques’ and the ‘Opus Postumum’, Forster, Eckart ed. (Stanford: Stanford University Press 1989), 29-46.Google Scholar This legal notion of a deduction refers to a justification of a claimed right and concerns only acquired rights- as opposed to innate rights.

47 See section 13 of the Transcendental Deduction (A 84-92/B 116-24). The following paragraph from that section makes the point under discussion very explicit: ’Let us take, for instance, the concept of cause, which signifies a special kind of synthesis, whereby upon something, A, there is posited something quite different, B, according to a rule. It is not manifest a priori why appearances should contain anything of this kind (experiences cannot be cited in its proof, for what has to be established is the objective validity of a concept that is a priori); and it is therefore a priori doubtful whether such a concept be not perhaps altogether empty, and have no object anywhere among appearances …. Appearances might very well be so constituted that the understanding should not find them to be in accordance with the conditions of its unity …. If we thought to escape these toilsome enquiries by saying that experience continually presents examples of such regularity among appearances and so affords abundant opportunity of abstracting the concept of cause, and at the same time of verifying the objective validity of such a concept, we should be overlooking the fact that the concept of cause can never arise in this manner. It must either be grounded completely a priori in the understanding, or must be entirely given up as a mere phantom of the brain. For this concept makes strict demand that something, A, should be such that something else, B, follows from it necessarily and in accordance with an absolutely universal rule. Appearances do indeed present cases from which a rule can be obtained according to which something usually happens, but they never prove the sequence to be necessary’ (A 90-1/B 122-4).

48 Gordon Brittan has very clearly captured this point in his adaptation of the semantic notion of presupposition to the discussion of the anti-reductionism in Kant’s philosophy of science. To distinguish presupposition from implication, Brittan defines the former as: ‘A presupposes B if and only if (a) if A is true, then B is true, (b) if (not-A) is true, then B is true.’ Thus, for instance, unlike the case of logical deduction, the analogue of modus tollens for presupposition does not hold. See Brittan, G.Kant’s Theory of Science (Princeton: Princeton University Press 1978), ch. 1.Google Scholar Brittan criticizes, and successfully shows to be wanting, other alternative views of ‘necessary condition’ (not discussed here) that preserve the deductive interpretation of the link between the categories and principles, and the rest of knowledge.