To speak of what is signifies making communicable what we know about it. But to know it, and communicate it, implies appealing to the generic, which is already an effect of semiosis, and depends on a segmentation of the content of which Kant’s system of categories, anchored to a venerable philosophical tradition, is itself a cultural product already established, culturally rooted, and linguistically fixed. When the manifold of the intuition is referred to the unity of the concept, the percipienda are by now already perceived just as culture has taught us to speak of them.2
Yet if a semiosic foundation is implied by the general framework of Kantian doctrine, that is one thing; it is entirely another question whether Kant ever developed a theory of how we assign names to the things we perceive, whether they be trees, dogs, stones, or horses. Given the question “How do we assign names to things?,” as Kant had inherited the problem of a theory of knowledge, the responses were essentially two. One came from the tradition that we may call “Scholastic” (but which begins with Plato and Aristotle): things present themselves to the world already ontologically defined in their essence, matter organized by a form. It is not important to decide whether this (universal) form is ante rem or in re: it is offered to us, it shines in the individual substance, it is grasped by the intellect, it is thought and defined (and therefore named) as a quiddity. Our mind has no work to do, or only insofar as the agent intellect does, which (wherever it may work) does so in a flash.
The second response was that of British empiricism. We know nothing of substances, and even if they existed, they would reveal nothing to us. For Locke, what we have are sensations, which propose simple ideas to us, either primary or secondary, but still unconnected: a rhapsody of weights, measures, sizes, and then colors, sounds, flavors, reflections changing with the hours of the day and the conditions of the subject. Here the intellect acts, in the sense that it works: it combines, correlates, and abstracts, in a way that is certainly spontaneous and natural to it, but only thus does it coordinate simple ideas to form those complex ideas to which we give the name of man, horse, tree, and then again, triangle, beauty, cause and effect. To know is to give names to these compositions of simple ideas. For Hume, the work of the intellect, as regards the recognition of things, is even simpler (we work directly on impressions of which ideas are faded images): the problem arises, if anything, in positing relations between ideas of things, as occurs in affirmations of causality. Here we would say that there is work, but performed without effort, by dint of habit and a natural disposition toward belief, even if we are required to consider the contiguity, priority, or constancy in the succession of our impressions.
Kant certainly does not believe that the Scholastic solution can be proposed again. Indeed, if there is truly a Copernican aspect to his revolution, it lies in the fact that he suspends all judgment on form in re and assigns a productive-synthetic, and not merely abstractive, function to the traditional agent intellect. As for the English empiricists, Kant seeks a transcendental foundation for the process they accepted as a reasonable way of moving in the world, whose legality was confirmed by the very fact that, when all was said and done, it worked.
At the same time, however, Kant noticeably shifts the focus of interest for a theory of knowledge. It is rash to say, as Heidegger (1997) did, that the Critique of Pure Reason has nothing to do with a theory of knowledge but is rather a questioning by ontology of its intrinsic possibility. Yet, it is also true, to quote Heidegger again, that it has little to do with a theory of ontic knowledge, in other words, of experience.
Nevertheless, Kant believed in the evidence of phenomena, he believed that our sensible intuitions came from somewhere, and he was concerned to articulate a rebuttal of idealism. But it appears to have been Hume who roused Kant from his dogmatic sleep, problematizing the causal relationship between things, and not Locke, though it was Locke who brought to the table the problem of an activity of the intellect in the naming of things.
A fundamental problem for the empiricists was saying why we decide, upon receiving sensible impressions from something, whether they refer to a tree or a stone. Yet it seems to have become a secondary problem for Kant, who was too preoccupied with guaranteeing our knowledge of heavenly mechanics.
In fact, the first Critique does not construct a gnoseology so much as an epistemology. As Rorty (1979) sums it up, Kant wasn’t interested in knowledge of but in knowledge that: not, then, in the conditions of knowledge (and therefore the naming) of objects. Kant asked himself how pure mathematics and physics are possible, or how it is possible to make mathematics and physics two theoretical fields of knowledge that must determine their objects a priori. The nucleus of the first Critique concerns the search to provide philosophical warrant for a legislation of the intellect regarding those propositions that have their model in Newton’s laws—and that, out of the need for exemplification, are sometimes illustrated by more comprehensible and venerable propositions such as All bodies are heavy. Kant is concerned to guarantee the knowledge of those laws fundamental to nature, understood as the totality of objects of experience. But he appears uninterested (at least until his Critique of Judgment) in clarifying how we know the objects of daily experience, what nowadays we call natural kinds, for example, camel, beech tree, beetle—with which the empiricists, on the other hand, were concerned.
Husserl, a philosopher interested in knowledge of, realized this, with evident disappointment (Investigation VI, ch. 8, para. 66):
In Kant’s thought categorial (logical) functions play a great role, but he fails to achieve our fundamental extension of the concepts of perception and intuition over the categorial realm.… He therefore also fails to distinguish between concepts, as the universal meanings of words, and concepts as species of authentic universal presentation, and between both, and concepts as universal objects, as the intentional correlates of universal presentations. Kant drops from the outset into the channel of a metaphysical epistemology in that he attempts a critical ‘saving’ of mathematics, natural science and metaphysics, before he has subjected knowledge as such, the whole sphere of acts in which pre-logical objectivation and logical thought are performed, to a clarifying critique and analysis of essence, and before he has traced back the primitive logical concepts and laws to their phenomenological sources.3
Husserl’s disappointment is converted into satisfaction for someone who maintains instead that the problem of knowledge can be resolved only in terms internal to language, namely in terms of coherence among propositions. And here Rorty (1979: sect. 3.3) takes issue with the idea that knowledge must be “the Mirror of Nature,” and he even asks how it was possible for Kant to assert that intuition offers us the manifold, when this manifold is known only after it has been unified in the synthesis of the intellect. In this sense, Kant would have taken a step forward with regard to the gnoseological tradition going from Aristotle to Locke, a tradition in which philosophers attempted to model knowledge on perception. Kant would have liquidated the problem of perception, insisting that knowledge concerns propositions and not objects.
Rorty’s satisfaction has evident reasons: although he proposes to challenge the very paradigm of analytical philosophy, it is this paradigm that is his point of departure, and therefore Kant seems to him to have been the first to suggest to the analytical tradition that we should not be asking what a dog is but rather what follows if the proposition dogs are animals is true.
What Rorty seems not to consider is that, if the opposition is between knowing what X is like and knowing what type of thing X is (as he himself quotes Sellars), we would still have to ask how one could respond to this second question without having responded to the first one.4 And it is worthwhile asking ourselves to what extent the opposition cited reproposes the old question (treated in Chapter 1 of the present volume) between encyclopedia and dictionary knowledge.
Kant’s position is still more embarrassing. He not only appears uninterested in explaining how we understand what X is like, bu
t also incapable of explaining how we decide what type of thing X is. In other words not only is the problem of how one understands that a dog is a dog and not a cat absent from the first Critique, but even the problem of how we are able to say that a dog is a mammal.
More than of a lack of interest on Kant’s part, we should perhaps speak of a cultural difficulty.5 Kant, as an example of rigorous knowledge constructible a priori, had mathematical and physical sciences at his disposal, as established and laid down from Newton onward, and knew very well how to define weight, extension, force, mass, a triangle, and a circle. On the other hand, he did not have at his disposal a science of dogs, beech or linden trees, or beetles. When Kant writes his first Critique, hardly more than twenty years had passed since the definitive edition of Linnaeus’s Systema naturae, the first attempt to establish a classification of natural species. The older editions of the classic Italian dictionary first published in 1612 by the Accademia della Crusca still defined a dog as a “well-known animal,” the attempts at universal classification like those of Dalgarno or Wilkins (seventeenth century) used taxonomies that we would today call approximate (as we have seen, in this volume, in both Chapters 1 and 11. This is why Kant spoke of empirical concepts, and often repeated that we couldn’t know all of the marks of these concepts. To take up our main point again, he was concerned by the fact that encyclopedic knowledge was potentially infinite. Thus the first Critique opens (Introduction, VII) with the declaration that concepts containing empirical elements must not appear in transcendental philosophy. The object of an a prior synthesis cannot be the nature of things, which in itself is “unlimited.”
But even if Kant had been conscious of reducing knowledge to knowledge of propositions (and hence to linguistic knowledge), he still would not have been able to formulate the problem, which Peirce on the other hand will formulate, of the nonexclusively linguistic but semiosic nature of knowledge. To be more precise, if he fails to do so in the first Critique, he will move in this direction in the third. But to be able to set out along this road, he needed to bring the notion of schema into the picture.
According to one of Kant’s examples, you can go from an unrelated succession of phenomena (there is a stone, it is struck by the sun, the stone is hot—and, as we will see, this is an example of perceptual judgment) to the proposition the sun heats up the stone (P, 23). Let us suppose that the sun is A, the stone B, being hot C, and we can say that A is the cause by which B is C.
The tables of categories, transcendental schemata, and principles of the pure intellect instruct us on how to proceed. The axioms of intuition tell us that all intuitions are extensive quantities and, through the schema of number, we apply the category of singularity to A and B. Through the anticipations of perception, applying the schema of Degree, the reality of the phenomenon (in the existential sense of Realität) supplied by our intuition is affirmed. Through the analogies of experience, A and B are seen as substances, permanent in time, to which accidents inhere. We therefore establish that accident C (heat) of B (stone) is caused by A (sun). And thus we finally decide that what is connected to the material conditions of experience is real (reality in the modal sense, Wirklichkeit) and applying the schema of existence in a determined time, we assert that the phenomenon is truly the case. Likewise, if the proposition was by the law of nature, it happens that always and necessarily the light of the sun heats up (all) stones, the category of unity should first be applied, and finally that of necessity. Accepting the transcendental foundation of synthetic judgments a priori (but this isn’t the matter in contention), Kant’s theoretical apparatus has explained to us why one can say with certainty that A necessarily causes the fact that B is C.
But why is A perceived as sun and B as stone? How do the concepts of the pure intellect intervene to make it possible to understand a stone as such, as distinct from the other stones in the heap of stones, from the solar light heating it up, from the rest of the universe? The concepts of the pure intellect that constitute the categories are too vast and too general to allow us to consent to recognize the stone, the sun, and the heat. Kant promises (CPR/B: 94) that once a list of pure primitive concepts has been designated, we will “easily” be able to add those derived from and subordinate to them; however, since at the present time he is concerned not with the completeness of the system but with its principles, he will reserve this supplement for another work. Furthermore, he informs us that in any case all we have to do is to consult the manuals of ontology, thus deftly subordinating the predicates of force, action, or passion to the category of causality, or the predicates of being born, perishing, or changing to the category of modality. But this is not enough, because we are still at such a level of abstraction that we are not able to say this B is a stone.
The table of categories does not allow us to say how we perceive a stone as such. The concepts of the pure intellect are only logical functions, not concepts of objects (P, 39). But, if we are not able to say not only that this A is the sun and this B is a stone, but also that this B is at least a body, all the universal and necessary laws that these concepts guarantee are worth nothing, because they could refer to any datum of experience. One could perhaps say that there is an A that heats up everything, whatever constraints there might be on variable B, but we still wouldn’t know what this entity is that heats things up, because variable A would remain unconstrained. The concepts of the pure intellect not only need sensible intuition, but also the concepts of the objects to which they must be applied.
The empirical concepts of sun, stone, water, and air are not very different from what the empiricists called “ideas” (of genera and species). Sometimes Kant speaks of generic concepts, which are concepts, but not in the sense in which he often calls concepts “categories,” which are indeed concepts, but of the pure intellect. Categories are extremely abstract concepts, such as unity, reality, causality, possibility, and necessity. We cannot determine the concept of horse through the application of pure concepts of the intellect. Horse is instead an empirical concept deriving from sensation, through comparison of the objects of experience.
Empirical concepts are not studied by general logic, which is not supposed to investigate “the source of concepts, or the way in which concepts have an origin, insofar as they are representations” (L I, 55, my emphasis). Nor are empirical concepts studied by critical philosophy, which deals not with “the genesis of experience, but about that which lies in experience”; of the two objects of study, “the former belongs to empirical psychology” (P, 21). We ought to say then that we arrive at the formulation of empirical concepts in ways that have nothing to do with the legislative activity of the intellect, which rescues the matter of the intuition from its own blindness. In which case we should know horses and houses either through their manifest quiddities (as occurred in the Aristotelian-Scholastic line of thought) or through a simple task of combination, correlation, and abstraction, as was the case for Locke.
There is a passage from the Logic that could confirm our interpretation:
In order to make our presentations into concepts, one must thus be able to compare, reflect, and abstract, for these three logical operations of the understanding are the essential and general conditions of generating any concept whatever. For example, I see a fir, a willow and a linden. In firstly comparing these objects, I notice that they are different from one another in respect of trunk, branches, leaves and the like; further, however, I reflect only on what they have in common, the trunk, the branches, the leaves themselves, and abstract from their size, shape, and so forth; thus I gain a concept of tree. (L, 100)
But the passage would be Lockean if a term like “understanding” were to retain what is, after all, its weak meaning of “Human Understanding.” Instead, this could not happen in the case of the mature Kant, who had already published the three Critiques. Whatever process the intellect goes through in order to understand that a willow and a linden are trees, it does not find this “treeness” in the sensible
intuition. And in any case Kant has not told us why having a given intuition allows us to understand that it is an intuition of a linden tree.
Even “to abstract” in Kant doesn’t mean take from or make spring from (which would still be the Scholastic prospective), and not even construct by means of (which would be the empirical position): it is purely considering separately, it is a negative condition, a supreme maneuver of the intellect that knows that the opposite of abstraction would be the conceptus omnimode determinatus, the concept of an individual, which in the Kantian system is impossible. Sensible intuition must be worked upon by the intellect and illuminated by general or generic determinations.
The cited passage perhaps responded to necessities of didactic simplification (in a text that gathers and certainly reelaborates notes taken by others in the course of his lectures, and is approved by an already mentally weakened Kant), because it is in clear contrast with what is said two pages before: “the empirical concept derives from the senses by the comparison of objects of experience and only receives the form of universality thanks to the intellect” (L 1, 3). “Only” here appears to be a euphemism.
13.2. Judgments of Perception
When Kant dealt with empirical psychology, in the decade preceding the first Critique (and here, too, we have to rely on lectures given somewhat under constraint and transcribed by others6), he already knew that knowledge provided by the senses is not sufficient, because it is necessary for the intellect to reflect on what the senses have offered it. The fact that we believe we know things on the basis of the sole testimony of the senses depends on a vitium subreptionis: from infancy we are so used to grasping things as if they already appeared given in our intuition that we have never made an issue out of the role performed by the intellect in this process. Not being aware that the intellect is in action does not mean that it is not working. Thus, in his Logic Kant alludes to many automatisms of this kind, such as when we speak, demonstrating that we know the rules of language; and yet, if asked, we wouldn’t be able to say what they were, and maybe we wouldn’t be even able to say they exist (L, Intro. I, 13).