Prolegomena to any Future Metaphysics (1783)
Immanuel Kant (Modern Library, 1949)
76 p. First reading.
History of Philosophy, Vol. VI, Part II: Kant
Frederick Copleston, SJ (Image Books, 1964)
277 p. First reading.
Kant: A Very Short Introduction
Roger Scruton (Oxford University Press, 2001)
141 p. First reading.
Kant is difficult. Coming in, I knew that his fame rested on a two-fold reputation: his being a challenging and important figure in the history of philosophy, and his having conveyed his ideas in prose of deep and abiding opacity. I’m not sure I grasp the reasons for the former, but I can damn well vouch for the latter. For the past four months I have been slowly chiseling my way through two short, but reputedly significant, works — the Prolegomena to any Future Metaphysics and the Groundwork for the Metaphysics of Morals — supplementing them with a few haphazardly chosen secondary sources. In this post I deal with the Prolegomena, and reserve the Groundwork for a subsequent post.
In truth, my diligence has been intermittent, owing partly to discouragement and partly to the jostle of affairs, which faltering partly explains why my understanding has not come into focus. In fact, I’m sure that I don’t really understand what Kant is saying. What I propose to do here is something quite modest: to try to articulate the issues and problems that motivated his philosophical effort (insofar as they pertain to these works), and to make some gestures in the direction of the kind of solutions he proposed. This will fall far short of what he deserves, but it will be a start, and it is the best I can muster under the circumstances.
The Prolegomena was published a few years after Critique of Pure Reason, and its purpose was to serve as a precis and a pointer to the larger work. Apparently Kant’s contemporaries failed to truly grasp the significance of his great work (surprise!), and so he penned the shorter work to clarify the main points and lure his readers to their deaths — or, I should say, to the Critique itself. In that sense, it has been written for beginners. Kant takes some time to sport with those readers who find even this entry-level version of his thought too difficult, kindly reminding them to “bear in mind that it is not necessary for everyone to study metaphysics”. I didn’t permit such asides to deter me.
The subject of discussion in the Prolegomena is metaphysics, and more specifically the epistemology of metaphysics: how is metaphysical knowledge possible, if it is possible? Roger Scruton’s instructive little volume reminds us that the essential background for understanding Kant is found in Leibniz and Hume. Leibniz’s Monadology had defended the position that the mind knows certain principles (such as the Principle of Sufficient Reason and the Principle of Non-contradiction) innately, and that these principles are intuitively known to be true. They form the indispensable foundation for all knowledge of contingent and particular things. Attempting to rely only on those innately-known principles, he articulated a complex metaphysical theory of substances, causes, perception, and so forth. He considered the content of his system to be objectively true because demonstrable on the basis of principles whose truth is intuitively perceived by everyone. He had a high view of the capacity of human beings to know truths about the world.
David Hume, on the other hand, articulated a skeptical view of human knowing. He argued that there are no innate ideas. Everything in our minds was first in our senses, and we have no source for knowledge apart from sensory experience. Leibniz’s innate principles are not principles at all, says Hume, but simply inductive generalizations on the basis of experience: we assert that every effect must have a sufficient cause only because we have so frequently perceived one phenomena (the effect) conjoined to another (the cause), but in fact not only can we not assert that effects must be conjoined to causes, we cannot even assert that effects are conjoined to causes. We can say only that there are phenomena, and we impose order on the play of phenomena not because the order is objectively present, but because that is how our minds attempt to deal with the flood of sensation. It is a position that takes a dim view of the capacity of human beings to know truths about the world.
It was into this stand-off between the “rationalist” side and the “empiricist” side that Kant ventured and set up his little writing desk. But before proceeding further a third historical influence deserves mention: the scientific revolution. Kant was deeply impressed — maybe too impressed — by the success of the sciences. The agreement and cumulative progress of the sciences was in sharp contrast to the disagreement and disarray of philosophy. The careful conceptual articulation, restrained epistemological claims, and systematic method of the sciences appealed to Kant, as they did to so many of his contemporaries, as holding forth a model for the secure founding and elaboration of knowledge. As he says in the Prolegomena, the sorry state of metaphysics in comparison to the sciences convinced him that metaphysics up to his time had been founded on false principles and trafficed in invalid concepts. (He illustrated this state of affairs with his famous antinomies, apparently valid arguments that lead to the conclusions that, inter alia, a necessary being exists, a necessary being does not exist, the universe is infinite in space and time, the universe is finite in space and time, every existing thing is simple or composed of simple parts, no simple things exist, there is freedom, there is not freedom. In other words, the existing methods and concepts of metaphysics lead to contradictions and cannot be a source of truth.) The overarching motive for his own philosophical project in the Critique was to secure a sure foundation for metaphysics by examining the operation of human reason (or is it of reason pure and simple?) and delineating its limits (with, I’m convinced, emphasis on specifically human limits). This philosophy, his so-called critical philosophy, was to be to previous philosophical systems what chemistry was to alchemy and astronomy to astrology: a source of true, if circumscribed, knowledge.
If I understand the matter rightly, then, Kant stakes out a position between Leibniz and Hume. On the one hand, he argues that our capacity to know the world is limited, and many historic metaphysical claims — about our knowledge of the world, or the soul, or God — are unsound. On the other hand, he opposes the thorough skepticism of Hume, articulating by close analysis of the inner structure of reason, reason’s capacity for true knowledge. At least, I think so.
With that context in place, we can start to explore the positive content of his system. In this, we will he helped by some definitions, for Kant makes a number of distinctions at the outset intended to clarify his questions. The first distinction is between analytic and synthetic propositions. An analytic proposition is one which is known to be true simply on the basis of the meaning of the words it contains. For example, “The whole is greater than a part” or “All bachelors are unmarried”. The predicate is already implicitly contained in the subject. In synthetic propositions, on the other hand, the predicate is not contained in the concept of the subject. For example, “Canada is north of the United States” or “All bachelors are unhappy”. The truth of these statements, if they are true, cannot be determined on the basis of the propositions themselves; independent evidence must be examined. The second major distinction Kant makes is between a priori and a posteriori propositions. The a priori propositions are necessarily true; they are true independently of experience. The gold standard of such propositions is the mathematical theorem. Propositions which might or might not be true, on the other hand, and which are known only through experience, are a posteriori. For example, “Frenchmen speak exclusively while holding marbles in their mouths”. Some philosophers, such as Hume, had identified analytic propositions and a priori propositions with one another, and likewise with synthetic and a posteriori propositions. They argued that a priori propositions, which are necessarily true, must be analytic, and by the same token the contingency of a posteriori propositions meant that they must be synthetic, known only through experience.
Kant, on the other hand, insisted that these two distinctions were distinct from one another. He agreed with Hume that all analytic propositions are a priori, but he argued, and by doing so opened up the passageway by which he would proceed, that some synthetic propositions are a priori as well. Such propositions are necessarily true, and their truth, including their necessity, is known on the basis of experience. Metaphysical propositions fall into this class, so Kant’s question “How is metaphysical knowledge possible?” can be rephrased as “How is synthetic a priori knowledge possible?” This question, note, must be answered before any metaphysical conclusions can be drawn. It is interesting — and apparently controversial — that Kant claimed that certain laws of nature are synthetic and a priori:
“…among the principles of this universal physics are to be found some that really possess the universality we require, such as the proposition: substance continues and is permanent, and that, according to fixed laws: all which happens is at all times previously determined by a cause. These are really universal natural laws, existing completely a priori.” (section 15)
It is at this point, with the challenge of defending the existence of synthetic a priori truths, that Kant’s real project begins, and it is at this same point that my understanding begins to falter. I will try: in order to explain how synthetic truths can ever be a priori (and therefore known to be always and necessarily valid), he launches into an examination of how we know. How is knowledge possible at all? What is understanding, and how does it function? What are the conditions for experience of the world? This exploration is quite difficult to follow in detail, but he leavens the dough with humorous comments now and then: “Since I had found the origin of the categories in the four logical functions of all judgments of the intellect, it was only natural to seek the origin of the ideas in the three functions of the syllogisms of reason” (Section 43). But of course!
What emerges from this discussion is a general picture of human knowing. It looks something like this: experience is a combination of raw sensation and the faculties of reason. All knowledge is situated and subjective (in the sense of belonging to a particular mind) and the sphere of possible experience is determined (in part?) by the qualities of that mind. We can know things only insofar as our senses and intellect permit us to experience them. We can never know anything outside of our experience, and so we can never know things-in-themselves; we can only know things under the aspects in which they appear to us when filtered through our sensory and intellectual apparatus.
The role of the faculties of reason in this picture is crucial. The very structure of reason, says Kant, affects our knowing. Before they can cohere into experience, all perceptions must be subsumed under certain concepts. These concepts he called “categories”, and he identified them (if anyone is still reading, they are: unity, plurality, totality, reality, negation, limitation, substance, cause, reciprocity, possibility, existence, and necessity). These are “pure concepts of the understanding”. They are the concepts by which we organize our experience, and without which experience is not possible. “They are not derived from experience, but. . .experience is derived from them” (Section 30). They condition or frame our experience, revealing such aspects of the world as we are able to perceive.
At this point, it might not be clear how this theory of knowledge bears on the original motivating question: how is synthetic a priori knowledge possible? If our knowledge really is totally derived from experience, how can we ever establish an a priori truth, which is always and necessarily true? The answer lies precisely in his account of the structure of intellect, and in giving it he strikes a blow at a certain understanding of objective knowledge. Take as an example the synthetic a priori proposition Kant proposed earlier: “all which happens is at all times previously determined by a cause”. We know this to be always and necessarily true not because we have discovered that nature is governed by laws of causality, but because experience itself presupposes such laws. This general line of reasoning holds true for all synthetic a priori propositions; they are a priori not because we somehow have objective knowledge that transcends our own limited experience, but rather the opposite: our very experience of the world presupposes that such propositions are true. The truths are not, then, truths “out there”, at least not as far as we can know; they are truths “in here”, as a consequence of the way we know. Kant puts the point very directly: “The intellect does not derive its laws (a priori) from nature but prescribes them to nature.” (Section 36) This centralizing of our cognitive capacities, his making them the measure of the world as we know it, is what Kant called his “Copernican Revolution” in philosophy.
Kant’s theory secures, therefore, a certain kind of objectivity: he can claim that certain truths can be demonstrated to any rational creature. But it is at the price of locating those truths in rationality itself, rather than out in the world. At least, this is how I understand him. In so doing he cuts us off from the world in a very real sense. Late in the Prolegomena, in a section entitled “Bounds of Pure Reason”, he agrees with this conclusion: we cannot, he says, know things-in-themselves, for they are not objects of possible experience for us. This does not mean that they do not exist, or that some other kind of intellect may not know them, or know them under different aspects, but it does mean that we may not know them in themselves. There is no pre-established harmony between our minds and the world as it is in itself. The things-in-themselves he called noumena, and our experience of them he called phenomena. This is an important distinction that I believe will come up again in the discussion of his moral philosophy, but for now I will not pursue it.
Perhaps at that I will draw my discussion of the Prolegomena to an end. There is much that I have left unsaid, and that because I couldn’t piece together anything coherent. I have not mentioned at all his “transcendental idealism”, nor his “transcendental psychology”, nor his “transcendetal method”. I simply don’t know what is meant by “transcendental” in this context. Perhaps I have discussed the concepts to which these terms refer, but I don’t know it. This is a matter to be resolved some other time.
I have many remaining questions. Foremost among them is whether Kant’s analysis of reason is intended to be an analysis of specifically human reason, or of reason in general. Certainly the kind of sensation which we can experience is tied to our specifically human nature — we see the visible spectrum, for instance, and not the radio spectrum — and so our sensory faculties affect the kind of knowledge of the world we can have. But this is different from Kant’s claim, which is that our reason, or reason in general, also affects in turn the kind of knowledge we can have. I am also unclear as to what aspects of metaphysics Kant believed his ideas left standing, and which parts he believed they demolished. The troubles in which metaphysics finds itself are due to our taking concepts derived from experience and extending them, invalidly, to realms beyond experience, and he certainly thought that large swaths of metaphysical argumentation consisted of this irresponsible and ultimately nonsensical extrapolation of ideas into realms where they have no validity. I believe that he argued that proofs of the existence of God were impossible, but I am unsure whether he may have moderated that conclusion somewhat (he was himself a theist, if I’m not mistaken). I also wonder whether there might be a self-contradiction lurking somewhere in his system. I don’t say that I see one, but in my experience attempts to make knowledge subjective or to situate and relativize knowledge are usually making surreptitious exemptions in their own favour.
And then there is the most important question of all: is it true? It is ironic that while Kant founded his system to drag philosophy out of the mire of clashing claims and establish it on secure, publicly accessible methods, the mire just won’t give up; it absorbs even him. There is no doubt that Kant is important, and that his ideas merit serious consideration, and I have seen philosophical histories that divide the whole history of philosophy into pre-critical and post-critical, making Kant’s thought the watershed. But it is not true that he has succeeded in his sociological goal: that of bringing unanimity and cumulative progress to philosophy. Whether this is because his system is ultimately flawed, or whether the explanation rests in other, less conclusive reasons (such as people’s inability to understand him), I don’t know. For my own part, I certainly don’t understand him. To some extent I understand what he claims, but I don’t understand the underlying reasons why he claims what he does. I am not attracted by his conclusions; I would want to defend a more robust and intuitive concept of objective knowledge, and I would want to defend the legitimacy of metaphysical inquiry. That desire doesn’t untie the tangled mess of arguments that constitutes metaphysical history, of course, but I would rather focus on making sound arguments than forsake the project altogether. Even if I did accept Kant’s general picture of knowledge being a combination of “the world” and our sensory apparatus and our intellectual faculties, it is not evident to me that this implies we do not know things-in-themselves. May not the world and our sensory apparatus and intellectual faculties be such as to function in harmony? Kant may have assumed that they did not, but I wonder if he offered any arguments to that effect.
Since this discussion is getting over-long, I will conclude here and take up Kant’s moral philosophy in another Book Note. If you read this far, you have my sincere regard and admiration.
Many a naturalist of pure reason (by which I mean the man who believes he can decide in matters of metaphysics without any science) may pretend, that long ago by the prophetic spirit of his sound sense, he not only suspected, but knew and comprehended, what is here propounded with so much ado, or, if he likes, with prolix and pedantic pomp: “that with all our reason we can never reach beyond the field of experience.” But when he is questioned about his rational principles individually, he must grant, that there are many of them which be has not taken from experience, and which are therefore independent of it and valid a priori. How then and on what grounds will he restrain both himself and the dogmatist, who makes use of these concepts and principles beyond all possible experience, because they are recognized to be independent of it? And even he, this adept in sound sense, in spite of all his assumed and cheaply acquired wisdom, is not exempt from wandering inadvertently beyond objects of experience into the field of chimeras. He is often deeply enough involved in them, though in announcing everything as mere probability, rational conjecture, or analogy, he gives by his popular language a color to his groundless pretensions. (Section 31)