EPISTEMOLOGICAL IMPLICATIONS OF KANT’S COPERNICAN REVOLUTION
作者:Tom Rockmore
Tom Rockmore
This paper will provide some results from a work in progress. Over the course of many years I have been interested in German idealism in a broad sense and in epistemology, two themes that are usually understood as unrelated. I see these two themes as as closely related. I freely admit that my view is controversial, even heretical. A further heresy concerns my understanding of German idealism. By German idealism I have in mind a debate including at least Kant, an idealist by any description, who is sometimes, especially in the English-language debate, omitted from the idealist canon, often by Anglo-American analytic philosophers like Rorty interested in Kant without the machinery. I also have in mind the great post-Kantian German idealists Fichte, Schelling and Hegel, and, in my view Marx. I believe Marx’s position can best be understand, not as non-philosophical, but as philosophical, as a further extension of Hegel’s.
I agree with almost all observers in understanding the critical philosophy as concerned with knowledge. But I reject Kant’s influential claim that epistemology ends with the critical philosophy. And I reject as well the associated claim that after Kant philosophers no longer understood science. In Kant’s wake, there were three main attitudes toward the critical philosophy. Some philosophers opposed the very idea of a transcendental analysis of reason. Some, most prominently Maimon, thought that Kant’s project was incomplete and needed to be completed, not abandoned. Still others were concerned with carrying the critical philosophy beyond Kant. Kant typically claims that other than stylistic changes his position cannot be improved on or altered in any way without causing all of human reason to shaking the foundations of human reason. In his wake, the post-Kantians exploited his own distinction between the spirit and the letter of a theory in trying to extend the critical philosophy beyond Kant.
How does one know what the spirit of the theory is? Kant is of two minds on this question. In drawing attention to this distinction, he suggests one can determine what the spirit of a theory is.[i] This commits him to hermeneutical essentialism, to the idea that one can in fact get it right about a text. He also suggests that an original thinker may not know what is central to the new theory, which is only determined by those who later consider it.[ii] This implied that Kant himself may not have fully grasped what his critical philosophy was about, its central insight, in his word its spirit.
What is the spirit of the critical philosophy? For a long time I thought the central element in the position was the idea of system. Kant clearly indicates that science must take shape as a system.[iii] Kant’s view of system remains problematic. He seems never to have made up his mind on this important question. I believe a close reading of the Critique of Pure Reason will show that he is simultaneously committed to two different, incompatible conceptions of system. One borrowed from Descartes, and then refined by Lambert, is the standard quasi-geometrical conception of system. The other, due to Wolff, is the idea of a system as a mere congeries. These ideas of system are incompatible. There is no way to bring together a view of the critical philosophy as exhibiting a system in the quasi-geometrical and in the Wolffian senses. It is plausible that someone reacting to Kant would share his view that science must take shape as system while believing that system in question was lacking in the critical philosophy. One way to understand later German idealism is as an effort running at least through Fichte, Schelling and Hegel and perhaps Marx to work out the idea of philosophical system, in a word to provide the system on which Kant himself insists but fails to provide.
More recently, I have come to think that deeper than the idea of system lies the famous Copernican revolution in philosophy. Kant’s Copernican revolution, or Copernican turning, is frequently mentioned, mentioned by nearly everyone who writes on Kant, but not often discussed in detail, and little understood. There is little agreement about what it means, what, if anything it has to do with Copernicus, and even whether it exists.
The aim of this paper is to make some remarks, from an American point of view, on the epistemological implications of Kant’s Copernican turning for knowledge today. I will be arguing that Kant correctly sees that knowledge is possible only through some kind of constructivism which he is unable to elucidate and that Hegel correctly indicates the direction such an elucidation must take.
On interpreting Kant’s Copernican turn
It is pointless to speculate about the epistemological implications of Kant’s Copernican turn before we understand what he is in fact claiming. One of the reasons that more has not been written about the Copernican turn is that it is so difficult to interpret it. At least in English-language circles, doubt subsists about whether there is anything like a Copernican turn in Kant’s writings and whether it has anything to do with Copernicus. Students of Kant divide on these issues.
To the best of my knowledge, the most comprehensive account of Kant’s Copernican turn is given by Hans Blumenberg.[iv] Blumenberg, who is concerned to minimize any relation between Kantian philosophy and Copernican astronomy—he points out there is no conclusive evidence Kant read Copernicus—reconstructs Kant’s place within his intellectual context in some detail.[v]
Kant certainly never uses the term “Copernican revolution” to refer to his position. Yet since he was very familiar with and interested in such aspects of the new science as astronomy, cosmogony and Newtonian mechanics, it is plausible to think he was at least broadly familiar with heliocentric astronomy. It is then at least interesting that his contemporaries Herder, Reinhold and Schelling employ closely similar terms. In referring to the change from the Ptolemaic geocentric to the Copernican heliocentric system, Herder argues that philosophy must become philosophical anthropology[vi]. In the first letter of his Briefe über die Kantische Philosophie, which appeared in August 1786, hence before the second edition of the Kritik der reinen Vernunft, Reinhold refers to the relation between Kant and révolution[vii], and then to Kant and Copernicus[viii]. In a Nachruf on the occasion of Kant’s death, Schelling suggests that Kant intends to make a Copernican turn. [ix]
Copernicus’ astronomical turn
Let us suppose, for purposes of argument, that Schelling is right. Where does the Copernican turn lie? I see at least four passages in the first Critique as bearing on this question.[x] In claiming that Kant makes a Copernican turn and in examining its epistemological consequences I will have in mind these passages and others I will not have time to discuss.
Is Copernicus relevant to the critical philosophy? Kant suggests the relevance of Copernicus for understanding the peculiar epistemological success of modern science. He points to the Polish astronomer as setting the stage for all later science. In Kant’s eyes, in leaving behind Ptolemaic geocentrism in favor of heliocentrism, Copernicus proposes a kinematic analysis that makes possible Newton’s dynamical theory. It is reasonable to understand Kant’s critical philosophy as generalizing his understanding of the philosophy of science, and it is reasonable to understand his philosophy of science as generalizing his understanding of Copernicus’ relation to later science.
In responding to Ptolemy, Copernicus is concerned through heliocentrism to save the uniformity of motion that he believes cannot be saved through geocentricism. Like Ptolemy, in De revolutionibus[xi] Copernicus acknowledges that, except for the earth, the whole world appears to revolve daily from East to West with antagonistic revolutions by the sun, moon and so-called wandering stars (I, 4, p. 513). He holds that their regular, circular movements only appear to us as irregular (I, 4, 514), hence supposes the capacity to distinguish appearance from reality. He distinguishes apparent change with respect “either of the thing seen or of the spectator” (I, 4, p. 514). He suggests that in claiming that the earth is at the center of the world, it might be possible to explain the apparent irregular of perceived motion (I, 4, 515). According to Copernicus, the earth cannot lie at the center of the apparently irregular movements of the planets (I, 9, 520-521). In an account of the celestial orbital circles, he says, on the basis of simplicity, that the sun is immobile since its apparent motion can be attributed to the earth (I, 10, 525). He further indicates that in specifying, or as he says deducing, the terrestrial movements he will explain why it appears that even the fixed stars move (I, 10, 526).
Let us leave to oneside numerous unanswered questions such as: does Copernicus really overcome Ptolemy? Or: In what sense is Copernican astronomy original? Copernican astronomy is modern in at least three senses: the application of mathematics to nature in anticipation of Galileo and Newton, the reliance on the subject as constituting reality, which anticipates the Copernican revolution in philosophy, and in linking science to the capacity to explain the phenomena in independence of other commitments (to theology and science). In favoring circular orbits but interchanging the sun and the earth, Copernicus provides what is merely a version of the Ptolemaic model,[xii] a simpler, cleaner, more desirable version, but still in fact a form of the old geocentric model dressed up in new clothes, which is kinematically equivalent to its Ptolemaic predecessor.[xiii] But from the dynamical view, the theories are not equal but unequal since only the Copernican theory is compatible with Newtonian mechanics. [xiv]
Copernicus and Kant’s Copernican turn
Copernicus reverses Ptolemaic geocentrism in which the earth is motionless but the sun moves for heliocentrism in which the sun is motionless but the earth moves. His central insight can be described as the idea that the apparent retrograde motion of the fixed stars can be explained on the assumption that not the sun but the earth is in motion. He adopts a humanist form of science in making cognition depend on the finite human subject, in this case on human beings located on the surface of the earth.
Kant quickly reverses Copernicus’ astronomical reversal in turning away from a real subject to a mere Platzhalter or epistemological posit legitimating an anti-psychologistic claim to know independent of time and place. Kant’s anti-humanist theory of knowledge supposedly elucidates the conditions of the possibility of experience and knowledge of objects for all rational beings as distinguished from what human beings in fact do or are in principle capable of doing.
I believe that Kant’s Copernican turn is multiply-determined by, at the very least, Copernican astronomy, and the desire to solve the problem of knowledge. Kant applies a version of the Copernican approach, understood as making possible modern science, to the general problem of knowledge in the critical philosophy. In the famous letter to his friend Marcus Herz, written at the beginning of the critical period, Kant writes: “What is the ground of the relation of that in us which we call “representation” to the object?”[xv] This is the problem he will analyze in detail in the first Critique, and to which the Copernican turn is the proposed solution.
The problem lies in understanding how representations relate to objects. For Kant, who draws attention to the distinction between a representation and an object, cognition relies on grasping an external object through its representation. This leads to twin claims which structure Kant’s epistemological theory: we cannot know an independent object, or one to which there is no epistemological link; and we can only know what we can be said to “construct” (herstellen). Kant’s constructivist epistemology consists in claiming that subject representation grasps, or what is the same thing correctly represents, the mind-independent cognitive object it “constructs.” In other words, the mind-independent cognitive object is transparent to mind for the reason that we construct it, as Kant says, according to a plan of our own.
Some difficulties in Kant’s proposed solution
Kant famously suggests he knows Plato than the latter knew himself.[xvi] His problem is a form of the ancient problem of representation already analyzed by Plato in the Republic. We recall that Plato criticizes art and poetry for providing imitations twice removed from the real. We recall his suggestion that some people, call them men of gold, on grounds of nature and nurture, can directly grasp reality and truth.
Since it is difficult to take Plato’s suggestion seriously, it appears that he leaves us with an unresolved difficulty. In denying that representations are knowledge, he denies a representational solution to the problem of knowledge. In insisting on a representational formulation of the problem of knowledge, Kant commits himself to its solution on anti-Platonic, representational grounds.
I believe that the problem of representation, or knowing that representations represent, remains unresolved in Kant as well. His Copernican solution to the problem of representationalism is problematic for several reasons.. One series of problems derives from the very idea of an analysis of pure reason. As Hamann quickly pointed out, it is difficult to understand how reason can sit in judgment on itself. This type of problem, which arises in any claim for knowledge apart from and in independence of the surrounding context, appears to undermine the real possibility of a transcendental analysis as Kant understood it. Except in very restricted situations, one cannot make sense of the conditions of possibility of knowledge in the Kantian sense.
A second series of problems derive from Kant’s view of the thing-in-itself. Jacobi’s famous remark points to Kant’s inability to explain either how knowledge of mind-independent reality is possible or how we can do without this concept. The result is an obvious tension in his position between realism and constructivism. Kant’s problem is representationalist but his solution is constructivist. The problem calls for an analysis of the relation of the representation to the mind-independent external world, the object as it is in independence from us, in his language the thing-in-itself. Yet the constructivist solution tells us not how the representation relates to the mind-independent object but rather the condition of objects of experience and knowledge. A mind-independent external object is not the same as and cannot be reduced to an object of experience and knowledge. Since by definition a thing-in-itself can be thought but not experienced, reality is unknowable. In other words no analysis of the relation of the representation to the object is possible. Kant fails, then, to show that representations in fact represent. The idea of representation is inherently mysterious.
A third series of problems concerns the idea of constructivism. Kant not only does not provide such an account. In a well known passage he further claims that no account can possibly be provided.[xvii] He is left with the inability to explain how what is in principle a condition of the possibility of knowledge in general for all rational beings can be true for human beings. This is a subset of the wider series of problems of understanding how knowledge is possible for human beings or real cognitive subjects. He has no way to explain the relation between the cognitive capacities he attributes to his conception of subjectivity and what finite human beings are capable of doing.
The Kantian problem of knowledge and constructivism
Kant’s Coperican turns suggests that, since we cannot know we know mind-independent reality, a theory cannot be based on realism as ordinarily understood. It further suggests we cannot appeal to externalism for epistemological purposes. It finally suggests Kant is correct to rely on constructivism though unable to formulate it adequately. These three points form the basis of any further effort to develop the Copernican turn beyond Kant. I believe they form the basis of any effort after Kant to continue theory of knowledge.
The idea that to know means to know the mind-independent real goes back in the tradition to Plato, even to Parmenides. Let us distinguish between Plato and Platonism, since we cannot now determine Plato’s view. Platonic realism is the view there is a mind-independent real and under appropriate conditions it can be known. In our time, versions of Platonic realism have been formulated by Putnam, Devitt, Davidson and many others. Putnam’s internal realism can be paraphrased as the claim for different interpretations of a single permanent real. Yet it has never been shown that we know the real or even that a single mind-independent real exists.
There is a distinction between how to represent and what it means to represent. If representation implies ressemblance, there are any number of ways that two or more things can ressemble each other.[xviii] Representationalism in all its forms presupposes a correspondence view of truth. Yet since there is no way to know that the idea of the object corresponds to the object of the idea, there is also no way to know that a representation in fact represents.
Kant’s denial that we can know a mind-independent object undermines any effort to grasp what is as it is in favor of the idea we know only what, since we construct it, is transparent so to speak to the human mind. Kant did not know Vico, who did not influence German idealism before Marx. Yet the idea that we can know only what we construct is the basis of Vico’s famous claim that we make and know only history. [xix]
If Vico is correct, a theory of knowledge requires an account of human beings whose actions give rise to human history, which we know in knowing ourselves. Subject and object are identical since the subject “constructs” its object as a condition of knowing it. Vico’s humanist approach to knowledge depends on a revised view of the subject, not as an epistemological placeholder or a mere spectator, but as an actor, as a finite human being. In Kant’s wake, such an approach is worked out in a revision of the Copernican turn.
Terminus ad quem? Hegel and the Copernican turn
Fichte makes a crucial contribution in rethinking knowledge from the perspective of the finite human being, what he calls the self (das Ich). If knowledge presupposes a subject, and the only subject is one or more people, in rethinking the cognitive subject as finite human being Fichte makes it possible to elaborate a theory of human knowledge.Hegel takes a further decisive step toward perfecting the Copernican turn in developing what is in effect Vico’s solution to the epistemological problem. In the process, he transforms an a priori, hence ahistorical view of knowledge into an aposteriori, historical view of knowledge. Kant’s Copernican turn requires an identity between the representation of the object and the object of the representation. Hegel rethinks the problem of knowledge in his so-called identity philosophy (Identit?tsphilosophie) as the problem of the demonstration of the identity of subject and object, knower and known, epistemology and ontology.
This claim, which runs like a red thread through Hegel’s entire corpus from beginning to end, is already present in the Differenzschrift. It is usefully restated in the forward to the Ph?nomenologie des Geistes in an important text. Hegel here abandon realism, hence externalism, in favor of a view of knowledge as emerging from the progressive interaction and subsequent adjustment between the object given in consciousness, the theory to which it gives rise, and further experience which functions as a test of it. In denying direct knowledge, Hegel describes the process of knowledge as working out different categorial frameworks. Frameworks, which are neither true nor false, allow us to make cognitive claims which are true or false relative to the particular conceptual scheme. The knowing process is intrinsically historical, since theories arise in and hence depend on the historical moment.
Hegel transforms the a priorism typical of the critical philosophy into an aposteriori of knowledge while holding on to the constructivism central to the Copernican turn. He gives a reality that cannot be known, hence abandons representationalism, in depicting knowledge as concerned wholly and solely with what occurs in conscious experience. Cognitive objects depend on conceptual frameworks which literally construct them within the knowing process.
Kant’s Copernican revolution turns on his constructivist insight. He is certainly right that knowledge depends on constructivism of which he offers no coherent account. In offering a plausible view of constructivism as a historical process, Hegel makes a decisive contribution to working out the epistemological implications of Kant’s Copernican revolution. I believe that in the past two centuries, the most profound philosophical insight is the understanding of the historicity of everything human, including claims to know. One unexpected result of the great French Revolution was to show that what appeared to be reality itself that would stand forever was only a transitory human creation. As concerns knowledge, this correctly suggests that we do not know we know in independence of time and place, since all our claims are finally indexed to the historical moment, to what we ourselves are capable of doing. I believe the historicized version of the Copernican turn provides the horizon of the problem of knowledge at present. At this late date, almost all possible moves in working out an ahistorical theory of knowledge have already been made. I believe that the work of the new century will largely turn on working out a very different view of knowledge as thoroughly historical, an intrinsically humanist conception of knowing that so to speak returns behind Kant to Copernicus.
[i] See Immanuel Kant, Kritik der reinen Vernunft, Stuttgart: Philip Reclam, 1966, B xliv.
[ii] See Kant, Kritik der reinen Vernunft, B 862.
[iii] See, e. g., Kant, Kritik der reinen Vernunft, B 860.
[iv] See Hans Blumenberg, The Genesis of the Copernican World, translated by Robert M. Wallace, Cambridge: MIT Press, 1987.
[v] For analysis of the relation of Kant’s Copernican turn to Copernican astronomy, see “What Is “Copernican” in Kant’s Turning?” in Blumenberg, The Genesis of the Copernican World, pp. 595-614.
[vi] Herders S?mtliche Werke, ed. P. Suphan, IV 61.
[vii] See K. L. Reinhold, “Briefe über die Kantische Philosophie,” in Teutscher Zeitschrift, August 1786, 27, p. 124-125.
[viii] See Reinhold, “Briefe über die Kantische Philosophie,” p. 126.
[ix] “?hnlich wie sein Landsmann Copernikus, der die Bewegung aus dem Centrum in die Peripherie verlegte, kehrte er zuerst von Grund aus die Vorstellung um, nach welcher das Subjekt unth?tig und rühig empfangend, der Gegenstand aber wirksam ist: eine Umkehrung, die sich in alle Zweige des Wissens wie durch eine elektrische Wirkung fortleitete.” “Immanuel Kant” (1804), in Schellings Werke, Munich: Beck, 1958, Bd. III, p. 599.
[x] See Kant, Kritik der reinen Vernunft, B xii-xiii, B xvi-xviii, B xxii, and B 312-313.
[xi] Nicolaus Copernicus, On the Revolutions of the Heavenly Spheres, translated by C. G. Wallis, in Great Books of the Western World, Ptolemy, Copernicus, Kepler, edited by R. M. Hutchins, Chicago: Encyclopedia Brittanica, 1952, vol. 16: Ptolemy, Copernicus, Kepler. Cited in the text.
[xii] See Herbert Butterfield, The Origins of Modern Science, New York: Free Press, 1957, p. 43.
[xiii] See Hans Reichenbach, The Philosophy of Space and Time, translated by Maria Reichenbach and John Freund, New York: Dover, 1958, p. 211.
[xiv] Reichenbach, The Philosophy of Space and Time, p. 218.
[xv] Immanuel Kant, Philosophical Correspondence, 1759-99, translated by Arnulf Zweig, Chicago: University of Chicago Press, 1967, p. 71.
[xvi] See Kant, Kritik der reinen Vernunft, B 370.
[xvii] See Kant, Kritik der reinen Vernunft, B 181.
[xviii] See Nelson Goodman, Languages of Art, Indianapolis: Hackett, 1976, p. 6.
[xix] See Giambattista Vico, The New Science of Giambattista Vico, trans. T. G. Bergin and M. H. Fisch, Ithaca: Cornell University Press, 1970, § 331, pp. 52-54. For discussion, see Tom Rockmore, “Vico y el constructivismo,” in Cuadernos sobre Vico, 11-12 (1999-2000), pp. 193-199.
> 我来回应