Contents:
- Introduction
- Phenomena and Noumena: An Overview of the Concepts
- Substance and Kant’s Noumenon: Is Kantian Substance a Noumenon in the Kantian Sense?
- Conclusion
Introduction
In the section of the Critique on Phenomena and Noumena, Kant sets himself the goal not only of refining our sense of what is meant by the terms phenomena and noumena, but of showing how the terms may be applied. In doing so, he refines our sense of what we may or may not hope to know by showing where our understanding is limited in its employment. In attempting to draw those limits he may remind some readers of Wittgenstein in the Tractatus Logico Philosophicus or perhaps of C.S. Pierce in “What Pragmatism Is.” In any case, the basic principle according to which he operates is one likely to be familiar to readers of the Critique: “thoughts without content are empty, intuitions without concepts are blind” [B76]. That is, understanding requires both concepts and sensations.
The difficulty arises where our reason attempts to go beyond where the senses may keep its pretensions in check. Returning to the Introduction, recall that Kant writes, “though all knowledge begins with experience, it does not follow that it all arises out of experience” [B1]. Such knowledge is a priori and one of the main undertakings of the Critique is to explain the legitimate scope of such knowledge. It is another major goal of the critique to show that any synthetic a priori reasoning must be grounded in our experience of the world. Kant believes that the only way that our understanding may be extended conceptually without the aid of experience is through the analysis of concepts. The attempt to extend our knowledge synthetically in a way that is not grounded in our experience leads us into the realm of ungrounded speculation associated with the pretensions of metaphysics (see Kant’s remarks on metaphysics in the Introductions at B21-24).
In this section on phenomena and noumena, Kant applies these basic principles to the particular case of noumena and shows how our employment of the concept by our reasoning ought to be limited by the limits of our understanding. His guiding principle is that “the understanding can employ its various principles and its various concepts solely in an empirical and never in a transcendental manner” [B297]. It will be the goal of what follows to explicate the meaning of these lines.
Phenomena and Noumena: An Overview of the Concepts
Phenomena may be understood simply as discrete sensory experiences of events in the world. Kant terms (a) our direct cognitive experience of such phenomena an “intuition” of them. In the opening chapter of the Transcendental Aesthetic, he writes that phenomena arise only “in so far as the mind is affected in a certain way,” which is to say that it is upon being affected by a of stimulus of some kind (not a term Kant uses, but one that explicates the kind of receptivity he has in mind), that our experience of phenomena arises within us. Kant’s term (b) for the capacity for phenomena to arise in us (from a purely sensory point of view) is “sensibility.” In defining the term he writes,
The capacity (receptivity) for receiving representations through the mode in which we are affected by objects, is entitled sensibility. Objects are given to us by means of sensibility, and it alone yields us intuitions; they are thought through the understanding, and from the understanding arise concepts.”
B33
Phenomena are, in a sense, then the matter upon which our faculty of understanding works in the application of its concepts. Our concepts are, by the same analogy, the “forms,” (c) the shapes, that may be given to such sensory material. Finally, the “pure” concepts of the mind are those that are native to the mind and do not arise from experience, but are basic to the mind’s own capacity for understanding to function properly, to understand what it may understand in the reasoned application of its concepts. These concepts may thus be considered a priori (“from the prior”) in both a developmental and cognitive sense. Kant writes,
Concepts of objects in general thus underlie all empirical knowledge as its a priori conditions. The objective validity of the categories as a priori concepts rests, therefore, on the fact that, so far as the form of thought is concerned, through them alone does experience become possible. They relate of necessity and a priori to objects of experience, for the reason that only by means of them can any object whatsoever of experience be thought.”
B126
This picture of phenomena might seem rather more panoramic than might be necessary, but it will serve well as a way to address the topic of noumena. Kant, in fact, draws a distinction between two kinds of noumena in phenomenal terms. that is to say, in one sense noumena correspond to our notion of intelligible objects and in another they do not. Noumena in Kant’s (i) negative sense may be thought of as mental occurrences without any of the characteristics of phenomenal objects. Here is Kant’s own wording:
If by ‘noumenon’ we mean a thing in so far as it is not an object of our sensible intuition, and so abstract from our mode of intuiting it, this is a noumenon in the negative sense of the term.
B307
But furthermore, since they lack any sensible characteristics the categories of the understanding cannot be applied to them. Kant therefore reduces this negative notion of noumena to “things in themselves” that cannot be accessed by our understanding at all, being empty of any sensory content by which they might be contemplated [B311-312].
Nevertheless, he finds value in this negative sense of the noumenal. They are valuable insofar as they may serve as the basis for drawing a hard distinction between the content of sensible and purely intellectual concepts. At the same time, and by virtue of that fact, noumena may be said to serve as limiting concepts that divide the purely sensible from the purely intellectual. For Kant, any concept susceptible of being understood must have both empirical and conceptual dimensions; otherwise, it will fail to appear to us as a proper object of the understanding, just as our perception requires at least two dimensions for an object to appear to us as such. There Here again is Kant on this point:
What our understanding acquires through this concept of a noumenon, is a negative extension; that is to say, understanding is not limited through sensibility; on the contrary, it itself limits sensibility by applying the term noumena to things in themselves (things not regarded as appearances). But in so doing it at the same time sets limits to itself, recognizing that it cannot know these noumena through any of the categories, and that it must therefore think them only under the title of an unknown something.
B312
The positive sense is the one Kant rejects. Simply put, he does so because it invites the characterization of purely intelligible concepts as intelligible objects. In doing so, he rejects the traditional notion that there are two “worlds” of objects, one sensible, the other intelligible [B312]. Readers of Quine who are familiar with his preoccupation with ontological questions may notice here a similar kind of readiness to reduce the number of entities counted in our ontology. Ockham’s razor becomes a useful tool in both cases. Setting aside the issue of their further similarities, for Kant there is this guiding principle that emerges: “Understanding and sensibility, with us, can determine objects only when they are employed in conjunction” [B314].
Substance and Kant’s Noumenon: Is Kantian Substance a Noumenon in the Kantian Sense?
The question might be raised: is substance in the Kantian sense noumenal? Consider the following:
- On the one hand, substance fits the Kantian criterion for a noumenon because it is something contemplated intellectually rather than observed as a sensible object [see B307]
- On the other, substance for Kant is not merely an intelligible concept, but an essential foundation for the reality of objects insofar as we may experience them. So far as Kant is concerned, substance is the ontologically necessary foundation for our experience of time. It is the foundational permanent relative to which other things in our experience may be understood as transitory [see B225].
Substance, then, appears to stand on the line between something “objective” in our sensory experience and something purely conceptual and non-objective in an intellectual sense. Although it is not something we may immediately experience as a sensible object, it is nevertheless eminently real in its own right and may even be considered the basis for the intelligible reality of transitory objects in our experience. Put simply, in more technical yet straightforward terms, it is the ontological foundation for our experience of reality as we find it.
The Transcendental vs. Empirical Employment of Concepts and Noumena
The way Kant organizes his text in the section on Phenomena and Noumena makes answering this question less straightforward than it otherwise might have been. Certainly, he does not answer the question directly. He does, in fact, discuss substance in this section, but only as part of a broader discussion of his distinction between transcendental and empirical employment of concepts. Although the text does not address the question directly (as might have been hoped), it does arguably leave us with the tools to determine the answer by utilizing the transcendental/empirical distinction. It so happens that doing so can also be beneficial for acquiring a deeper and readier understanding of how the concepts are meant to fit together.
In a clear-cut sense, the transcendental employment of concepts might be considered simply the act of contemplating them as concepts. This may take the form of the contemplation of general concepts by which we are able to apply them to other concepts generally or, otherwise, specifically distinguish them from one another. For example, Kant writes,
The transcendental employment of a concept in any principle is its application to things in general and in themselves
B298
This employment is contrasted with the empirical application of concepts, which is “merely to appearances” [B298].
This distinction precedes the distinction between the positive and negative senses of the term “noumenon” but the two are inter-related. As was said above, the positive sense involves a category mistake of sorts, involving the misapplication of the term “object” to concepts that should be regarded as purely intellectual. Kant’s description of the negative sense spells this out:
If by ‘noumenon’ we mean a thing in so far as it is not an object of our sensible intuition, and so abstract from our mode of intuiting it, this is a noumenon in the negative sense of the term”
B 307
A 20th century philosopher might comment that Kant is gesturing toward a misuse of language where it is illicitly carried over from one domain of discourse into another. He does indicate this in a roundabout way-as illustrated by quote immediately above and his subsequent rejection of the positive sense of the term-by clarifying for us that the term “object” is misapplied to noumena as the term should be understood.
Notice that there is an affinity between “noumenon” in the negative sense and the transcendental employment of concepts. If one were to employ the concept “cat” transcendentally, for example, one would thereby be employing it noumenally, i.e. not with regard to the empirical reality of cats as sensible objects, but with regard to the concept “cat” as something abstract, as a specific or general concept, apart from our mode of “intuiting” phenomenally. Any concept, in other words, employed transcendentally involves an application to things in general and in themselves (compare the two quotes from B298 and 307 above).
Noumena and Scientific Thinking
But as Kant emphasizes elsewhere (B299), whatever this purely conceptual “in general” amounts to, it must always be applicable to a sensible object if it is to have any sense or meaning. An important piece of the Kantian puzzle is the recognition that the transcendental and empirical employments of concepts are interdependent when it comes to the project of determining the nature of things in the sensible world.
Kant envisions their proper inter-relationship as one that proceeds along what we might recognize as “scientific lines.” When it comes to understanding the Kantian position on noumena and his attempt to set limits to the spontaneous flights our reasoning can take, considering noumena as intelligible objects crosses precisely those lines: to do so would be to treat the purely conceptual as something empirical.
In the same way, noumena, being entirely without any sensible features, cannot be treated in the same scientific-objective manner because they lack any sort of objective existence. The noumenal, rightly understood overlaps with the purely conceptual, our field of concepts. Drawing the transcendental/empirical distinction together with this clarification of the usage of the term “noumenal,” it may be seen that, by B298 as quoted and discussed above, the noumenal coincides with the transcendental employment of concepts. Descartes’ example of a chiliagon may serve as an example. A 1,000-sided figure is perhaps impossible to visualize with any accuracy, but our reasoning about its properties does not depend upon our ability to do so. When the mind goes beyond images and embraces conceptual thinking, logic may be its guide. Being so aided, it may formulate deductions that can be empirically tested: if divided into two equal halves, will each figure have five hundred sides? Utilizing the chiliagon concept in both ways, we have an example of transcendental and empirical uses.
Application to Substance
We are now in a position to apply these distinctions to substance. Again, substance seems to stand on the line dividing the transcendental from the empirical since it has both phenomenal and noumenal aspects. Although it must exist for us as the necessary ontological foundation for the reality of change in the phenomenal world, considered in itself as the principle of permanence (recall B225) it is imperceptible. Despite its imperceptibility, it may nevertheless be considered intelligible through the categories as a whole inasmuch as (along with space) it coincides with all of them as their foundational element (unity, plurality, totality/reality, negation, limitation/substance, causality, community/possibility-impossibility, existence-nonexistence, necessity-contingency).
It is foundational in the sense that, along with space, it is necessary for the objective possibility of the emergence of these categories in our sensible experience and therefore for them to be recognized as elements of our understanding at all. Kant writes: “All appearances are in time; and in it alone, as substratum (as permanent form of inner intuition), can either coexistence or succession be represented.” It is both a necessary reality within our experience and something non-objective. As a concept, it may be treated quasi-empirically as an ontologically necessary underlying principle of permanence or transcendentally as the logically necessary concept that brings together the categories of our understanding.
Conclusion
In my judgment, the pure forms of our sensibility (space and time) ought to be regarded as admitting of an attenuated form of understanding in keeping with their quasi-empirical nature, that sets them apart, as objects of knowledge, from either purely speculative entities or sensible objects. Unlike the categories, for example, the pure forms of intuition are grounded in our sensibility, yet they are not directly sensible. The salient point here is not that we cannot know anything about them, but that, to the degree that we cannot sense them, our knowledge of them is correspondingly less than would be the case for sensible objects. As objects of knowledge, they should be characterized accordingly.
Yet, for that very reason, the epistemological issues they raise may be directly compared to those surrounding the traditional notion of substance. While they are in fact necessary for the very possibility of our experience of sensible, mutable, contingent objects, our cognitive access to them is limited by the very fact that if they were to be sensed directly, something else, some further substrate would have to be supposed to explain their existence in space and time. The Kantian observer of nature is thus constrained to suppose the real existence of space and time in an absolute sense And yet, their necessary, real existence cannot, in principle, be made manifest. We are constrained to acknowledge their existence as what might perhaps be called structural abstractions, that, if one is committed to Kantianism, might be taken on board as analogous to the deeper structural principles that make the encoding of our mental “software” possible.
Lastly, the picture of knowledge that Kantianism yields could be compared to that of an image composed of the puzzle pieces of understanding, the categories of understanding themselves. Both elements, the shapes of the pieces as well as the image itself, are necessary to a complete picture of knowledge in the broader sense. Experience might be thought of as the progressive, ongoing world of completing that puzzle. Space and time are properly metaphysical concepts in that they are necessary to the very existence of the puzzle itself.
