Reality and Impenetrability in Kant's Philosophy of Nature

Daniel Warren

• Publisher: Routledge
• Year: 2013
• Print ISBN:
  9780815340546
  9780815340546
• eBook ISBN:
  9781135728496
• Edition: 1
• Topic: Philosophy
• Subtopic: Philosophy History & Theory

This book highlights Kant's fundamental contrast between the mechanistic and dynamical conceptions of matter, which is central to his views about the foundations of physics, and is best understood in terms of the contrast between objects of sensibility and things in themselves.

Chapter One

Kant’s Critical Views Concerning the Category of Reality

The doctrine concerning the categories of quality (reality, negation and limitation), as expressed in the “Analytic,” is particularly obscure. There is little consensus among Kant commentators on the nature of the claim to be established in the section treating the corresponding principle (the “Anticipations of Perception”). And although most believe that it is particularly closely connected to Kant’s views on physical science, it is difficult to get from the commentators (e.g., R. P. Wolff, pp. 232–8) any clear sense of the significance of the discussion of reality in the Critique apart from its application in physics. And those (e.g., H. J. Paton, v. II, pp. 144–9) who do attempt to provide such clarification give no real sense of how Kant’s account of reality fits into the more general critical views expressed in the Critique. It is this latter question that I will be attempting to address in this chapter.

A central idea in Kant’s critical philosophy is that the categories, though they originate in the understanding, can have content only through their relation to sensibility. For only then can we grasp what kind of feature is being attributed to an object when a given category is ascribed to it.¹ Sensibility thereby provides us with something we require if we are to be capable of applying the category to objects. The doctrines that Kant elaborates concerning individual categories (or groups of categories) depend essentially on their relation to sensibility, and in particular to its form, i.e., the fact that its objects are spatiotemporal. An understanding of such a doctrine will depend on our appreciating what difference this “relation to sensibility” makes; it depends on our grasp of the contrast between the category viewed as a product of the understanding alone, and the category insofar as we can apply it to sensible objects. I will refer to this as the contrast between the “intellectual” and the corresponding “sensible” category.²

For many of the categories, in particular, those of relation and of quantity, there has been significant discussion by commentators of the difference that “relation to sensibility” makes. In the cases of substance and of cause, the legitimate use of the category depends on its relation to notions of temporal permanence and succession respectively. The case of quantity is more obscure, but it is recognized that, for Kant, the application of quantity-concepts in concreto is in some way associated with the notion of a temporal sequence, as, e.g., in counting.³ For both kinds of category the “relation to sensibility” is clearly serving as a condition for applying the category to the objects of experience. However, when it comes to the category of reality, and the categories of quality generally, there is little in the secondary literature which discusses the difference that the relation to sensibility makes.⁴ This point will serve to focus the more general concern with Kant’s critical views on the category of reality, which form the subject matter of this chapter. The main claim that I will be concerned to establish is that, according to Kant, we can only appreciate the contribution of sensibility to the category of reality once we understand the connection between the latter and the notion of a causal power.

1. Reality and Real Opposition

Traditionally, the notion of reality—in the sense which is relevant here—is the idea of a positive property as contrasted to something which is a mere negation, or an absence or privation.⁵ For example, being light or being hot might be contrasted with being dark or being cold. And then we would say that light is a positive property or a reality,⁶ while darkness is the mere absence of light, i.e., a mere negation. In another important class of examples, perfections (i.e., ways of being perfect—e.g., being just, or wise) are put forward as cases of realities. The point is that even if one can express a verbal symmetry in the relation between two predicates, there is a metaphysical asymmetry. In the world, light and dark are not on the same footing. And in this sense, the one falls under the category of reality, the other, under the category of negation. Accordingly, if one theory viewed a property (e.g., cold, or evil) as a reality and another theory viewed it as a mere negation (the mere absence of heat, or of goodness, respectively), this would be matter of genuine, substantive disagreement.

The category of reality is to be distinguished from that of actuality (existence),⁷ which is one of the categories of modality. When we subsume a concept under the category of reality, we are claiming that it represents a positive property rather than the mere absence of such a property. But we are in no way claiming that it is actually instantiated, so the category of actuality is not involved. Similarly, if we claim that a property, e.g., cold, is a mere negation, that it is the mere absence of (e.g.) heat and nothing positive in its own right, we are not denying that it is instantiated, nor, for that matter, are we claiming that it is. Furthermore, it should be noted that reality (i.e., a positive property) may be capable of degrees, but existence or actuality, as Kant understand it, is not.

Kant does at times use the term “reality” in a way that is much closer in meaning to “actuality” or “existence,” for example, when Kant opposes it to ideality, rather than to negation.⁸ Sometimes talk of the “reality” of a representation simply means that its object exists. It is important to distinguish this sense of “reality” from the meaning of the category of reality (i.e., positive property). However, it should be acknowledged that these are not utterly independent notions either. It is part of the traditional doctrine of reality that every possible object must have some reality (in the sense of the category of reality); something cannot exist at all if it has no positive properties.

A natural place to begin investigating the difference the relation to sensibility makes to the category of reality is a section of the Critique called the “Amphiboly,” in which Kant criticizes the views of the Leibnizian school. The general form of his criticism is as follows. Kant regarded the character of the cognitive faculties and their relations as the sole grounds for synthetic a priori knowledge, e.g., metaphysics. But in Kant’s view, the rationalists wrongly took the representational capacities of the understanding to be sufficient for representing objects a priori, and thus, for formulating the claims of metaphysics. His position was that, in addition, the representational resources of sensibility were needed in order to do this. The rationalists’ views rested, according to Kant, on two mistakes: first, that the character of the understanding could be a sufficient basis for a substantive metaphysical claim, and second, that only the understanding could be the ground for such a priori knowledge. And it was on account of these errors that the Leibnizians were led to their characteristic metaphysical doctrines (identity of indiscernibles, monadology, etc.).⁹ Thus, it is in these passages that we can see a particularly systematic account of the difference sensibility makes to the categories and claims of metaphysics.

For example, in Kant’s view, the rationalists believed that all numerical difference between objects had to be captured by the resources of the understanding alone. These resources were restricted to conceptual representation, where these concepts were specified by the marks or characteristics they include and by the ones they exclude. Differences in concepts were reducible to such differences in marks or characteristics. Thus all numerical difference between objects had to be capable of representation by some such difference in their concepts, and in particular, by a difference (logical incompatibility) which itself entailed the numerical difference of the objects represented. This led to a version of the principle of the identity of indiscernibles. But what was excluded was the possibility of distinguishing objects merely in virtue of their association with different parts of space (at a given time), for this was not a difference that could be captured in terms of marks or characteristic features.¹⁰ For Kant, this amounted to the exclusion of a resource for distinguishing objects which has its origin in the faculty of sensibility, i.e., the representation of space. Thus, the metaphysical doctrines concerning the categories of quantity (numerical unity or diversity) depended in crucial ways on the role sensibility plays in representing objects.

Now what does the “Amphiboly” section say about the difference sensibility makes to the categories of quality, and to reality in particular? On the account presented there, the contrast between the phenomenal category of reality, on the one hand, and the supposed intellectual category, on the other, concerns the possibility of “opposition”¹¹ between realities, i.e., between real properties. Insofar as realities are taken to be objects of the pure understanding alone, such opposition is purported to be impossible. For phenomenal realities, on the other hand, conflict is possible and is readily observed in experience. Accordingly, Kant’s strategy in this part of the “Amphiboly” is to show that once we take account of the difference the relation to sensibility makes, we will see how to avoid the rationalists’ doctrine that opposition between realities is impossible, just as we saw earlier how to avoid the doctrine of the identity of indiscernibles.

Kant discusses the concept of opposition between realities, or “real” opposition, at great length in a pre-critical (1763) essay entitled “Versuch den Begriff der negativen Gröβen in der Weltweisheit einzuführen” (“An Attempt to Introduce the Concept of Negative Magnitudes into Philosophy,”¹² hereafter abbreviated “NG”) This is one of the important early works in which Kant first explicitly sets himself up against the followers of Leibniz and Wolff. Kant contrasts two sorts of opposition: logical, which is an opposition between two determinations based on mutual contradiction, and real, which is initially explained as an opposition which is not based on the principle of contradiction. (NG, §1, Ak. 2, 171). This merely negative characterization of real opposition might seem to suggest that it concerns incompatibilities such as obtains between being red and being green. (I am here assuming that this incompatibility is not based on logical contradiction.) That is, it might seem that real opposition obtains between two properties when it is impossible (but not logically impossible) that a single object have both. But when we look at Kant’s account of real opposition we find that he has something quite different in mind.

Kant’s typical example of real opposition is that of two equal moving forces acting in opposite directions, such as obtains when a single body exerts both a force of attraction as well as an equally strong force of repulsion. By contrast both with logical opposition and with the non-logical red-green incompatibility, Kant presupposes that an object can be endowed with (really) opposed powers, not that it cannot. The issue is not one of mutual incompatibility (whether logical or not), but of some intuitive notion of cancelling one another out.

So Kant believes that the Leibnizian rationalists denied the possibility of such cancelling out because they ignored the role of sensibility in the representation of objects.¹³ But once we recognize the difference that the “relation to sensibility” makes, Kant claims, we can see that it is indeed possible, at least in the world of appearances. Yet this still leaves it entirely unclear why the role of sensibility makes this particular difference. Moreover, how are these issues about the mutual cancellation of positive properties, or realities, related to a contrast between intellectual and sensible categories which is recognizably concerned with the general conditions for applying the category to objects of experience? To be sure, the mutual cancellation of opposed forces involves the opposition of spatial directions, and the representation of space is one of the conditions Kant attributes to our faculty of sensibility. Kant tells us that much in his discussion of real opposition (A283/B339). But there is no obvious reason why this opposition of spatial directions should be generally relevant in applying concepts of realities in experience. After all, though forces are associated with a spatial direction, this would seem to be a special case. And Kant includes all kinds of sensible qualities, e.g., brightness, heat, redness, etc., among the realities that objects of experience can have. A “critical” account of the category of reality would purport to cover these cases as well. What we need is a general account of the contribution of sensibility, which would explain the role of spatial direction in certain special, albeit central, cases. So we are still left with the question: what, in Kant’s view, is sensibility’s contribution to the most general conditions for applying the category of reality in experience? After addressing this question in a general way, I will return, in the final section of this chapter, to issues specific to the idea of real opposition.

2. Reality and Sensation

I now begin a more systematic approach to contrasting the intellectual reality-category with the phenomenal, and thus, to characterizing the difference that the relation to sensibility makes. As we said earlier, a category, insofar as its meaning is derived from the understanding alone, is a mere logical function. That is, it is a certain kind of logical role a concept (or, more generally,¹⁴ a “given cognition”) can play in judgment. A concept falls under the category of substance, for example, if it must always be considered the subject of a judgment and never the predicate.¹⁵ (See B129, A147/B186, A242–3/B300–1, B288.) Now the pure (unschematized) category of reality corresponds to “that determination which can be thought only through an affirmative judgment” (A246, cp. Maier, pp. 43–46). Reality is identified with “pure assertion” (B328/A272) and, elsewhere, with “sheer affirmation.” (B336/A280) The logical role associated with the category of reality is that of ascribing a predicate which contains no negation within itself.

This formulation of the content of the unschematized category of reality needs some explanation. In this context, it is assumed that a predicate-concept can be formed from other concepts by negating or conjoining them. To “contain no negation within itself” means that, when the predicate-concept is subjected to logical analysis, it is not found to be made up of any negated parts (or, perhaps, that it is logically equivalent to one not made of such parts). If we assume that all concepts are formed, ultimately, of fundamental parts,¹⁶ then a concept would represent a reality just in case (i) it is (or is logically equivalent to) one of these basic parts, or (ii) it is (or is logically equivalent to) a conjunction of one of these fundamental parts with a concept representing a reality (the point here being that conjunction—or whatever is logically equivalent to it—is the sole logical operation under which reality is preserved). Naturally, all of this presupposes a genuine asymmetry between the fundamental concepts and their negations, though they are obviously interdefinable.

According to the passages discussed earlier from the “Amphiboly,” the rationalists supposed the impossibility of conflict between realities to follow from their being “pure affirmations.” Mutual conflict arises, on their account, only when some negation is present. In other words, some property, whose concept is A, is in opposition to another property, whose concept is B, only when one of these concepts contains a part (a conjunct, say, C) whose negation occurs in the other. Thus, for example, asserting A of a thing, insofar as it involves asserting C of it, is incompatible with asserting B, insofar as that would involve denying C. But this sort of situation cannot arise if A and B are “pure assertions.”¹⁷

Needless to say, Kant thinks that...

Table of contents

• Cover
• Title Page
• Copyright Page
• Table of Contents
• Acknowledgements
• Note on References and Translations
• Introduction
• Chapter One Kant's Critical Views Concerning the Category of Reality
• Chapter Two Inner Determinations and Relations
• Chapter Three Dynamical and Mechanistic Conceptions of Impenetrability
• List of Works Cited
• Index