The Argument from Objective Reality

Idealism lies at the heart of the Copernican Revolution. Kant repeatedly stresses the key to escaping from the predicament is to see appearances as representations. Furthermore, it helps foster the other two consequences: the reconceptualization of schemata and the introduction of transcendental synthesis.

While Kant formulates a variety of arguments for idealism, it is usually thought that idealism depends on the results of Transcendental Aesthetic. Indeed, Kant’s official direct arguments do find themselves in Transcendental Aesthetic. However, in Transcendental Deduction there is one independent argument for idealism directly bearing upon the relation of a priori concepts to objects.

This most explicit connection between the Copernican model of mind and world with idealism appears in the very last section of A-Deduction, which is titled with “Summary representation of the correctness and unique possibility of this deduction”. The argument shows how to proceed from the Copernican model to its implication, and how idealism is a consequence of the Copernican model of mind and world:

If the objects with which our cognition has to do were things in themselves, then we would not be able to have any a priori concepts of them at all. For whence should we obtain them? If we take them from the object (without even investigating here how the latter could become known to us), then our concepts would be merely empirical and not a priori concepts. If we take them from ourselves, then

132 that which is merely in us cannot determine the constitution of an object distinct from our representations, i.e., be a ground why there should be a thing that corresponds to something we have in our thoughts, and why all this representation should not instead be empty. But if, on the contrary, we have to do everywhere only with appearances, then it is not only possible but also necessary that certain a priori concepts precede the empirical cognition of objects. For as appearances they constitute an object that is merely in us, since a mere modification of our sensibility is not to be encountered outside us at all. (A128-A129)

This characteristic Kantian argument can be reconstructed as follows:

(1) The objects of cognition are either things in themselves or representations.

(2) If the objects of cognition are things in themselves, then either object makes the concept possible, or the concept makes object possible.

(3) If it is the case that the objects make the concepts possible, then concepts are empirical, which contradicts with the apriority of the concepts in question.

(4) If it is the case that concepts make objects possible, then the concepts are empty, which contradicts with the reality of the concepts in question.

(5) The objects of cognition are not things in themselves.

(6) The objects of cognition are representations. (from (1) and (5))

For (1) and (2): Premise (1) is a conceptual truth. Everything can be either mind-independent or mind-dependent. If something is former, it is the thing in itself; if it is latter, it is representation.

Premise (2) formulates a grounding dilemma with which we have engaged ourselves.

For (3) and (4): The reducio assumptions in (3) and (4) are that there are concepts that are both a priori and objectively real. By assuming that a priori concepts are related to objects, this argument begs the very question of transcendental deduction. It does not argue for the truth of the Copernican model, but assumes it without justification. What the argument intends to show is what follows if we assume that the Copernican model that a priori concepts determine objects. Or more precisely, it intends to show what demand the Copernican model makes upon the metaphysical nature of the objects in question. It poses the urging question on what kinds of metaphysics of objects we should accept. Since we are concerned with idealism as a consequence of Copernican model of

133 representation and object, this argument is precisely the one we need to call for right now, and it is very suitable to place it here.

As is made clear by (2), (3), and (4), as long as we cling to a realistic metaphysics, pure concepts cannot be possibly related to objects. If the two horns of the dilemma must be rejected, it does not imply the falsity of the reductio assumption and thereby cancel the question that poses this dilemma.

It instead reveals that the problem lies in some implicit assumption that underlies the way in which the dilemma is formulated. This implicit assumption is nothing but the metaphysical reality of physical objects that serve as the objects of cognition. With the help of the reductio assumption, the rejection of the two horns of the dilemma constitutes a fatal attack on the presupposed realistic metaphysics of physical objects.

What is particularly noteworthy is the claim in (4) that if the objects of cognition are things in themselves, then the a priori concepts would be empty. The rejection of the second horn of the dilemma in a realistic framework shows that even if we have a priori concepts, provided a successful derivation of a priori concepts is available, the pure concepts could not be applied to objects at all and remain to be merely “subjective conditions of thinking” (A89/B122). If objects were utterly independent of the subject, then the gap between mind and world is too huge to be closed. The world has nothing a priori to do with mind, and mind can do nothing a priori to the world. It is wildly impossible to suppose that the human mind can make a broadly causal difference on a mind-independent world.¹⁶⁵ Only divine mind can make actual the object by merely intuitively representing it. In any case, the human mind cannot elevate their spontaneity up to the divine level. Therefore, the moral is that the world must exist in such a way that it can be compromised by the mind.

When the realistic metaphysical assumption is replaced by the idealistic one, the dilemma posed by Kant’s puzzle does not disappear but reemerges anew. In the new dilemma in an anti-realistic framework, there likewise exist two parallel alternatives: either the object makes the concept possible, or the concept makes the object possible. In the first case, it suffers from the very same objection to the first horn of the realistic dilemma, for what is in play is still the borrowing model of knowledge.

It is intriguing that the empiricist epistemology is independent of the kind of the metaphysics of objects that is adopted. Even if the objects of cognition are merely representations, the borrowing model of knowledge still merely copies the content of these representations and

165 Behind the limitation of making causal difference is the idea of ontological hierarchy. The conception of ontological hierarchy is also evident in Kant’s argument from laws of nature that will be discussed later, and the similar point is also made in Chapter 8.

134 therefore it cannot say anything more than what these representations teach it. However, the realism and idealism of physical objects differ only in metaphysical status, rather than in content.

The empiricist epistemology is liberated from its underlying metaphysics.

This striking feature has profound implications. For one thing, empiricist epistemology, if properly qualified, is a deeply plausible epistemology. The independence of the empiricist epistemology from metaphysics implies that it is compatible with any kind of metaphysics. A properly qualified empiricist epistemology extends its theoretical viability and utility as far as it could be matched with metaphysics.

For another, empiricist epistemology is theoretically neutralized. Although a realistic metaphysics could be matched only with empiricist epistemology with regard to empirical knowledge, it does not imply that the reverse also holds. Indeed, an empiricist epistemology intended to match realistic metaphysics provides a convincing account of a scope of knowledge.

But it does not add any theoretical virtue when compared with its rival theories. As we have seen, both Plato’s rationalist epistemology and Kant’s own epistemology can incorporate and appropriate a qualified empiricist epistemology without any compromise to the coherence of their own position.

The aftermath of the Copernican move is not exhausted by this argument for idealism. The idealist claim that objects of cognitions are indeed appearances does not by itself suffice for the solution to the problem with respect to how representations can a priori determine objects. What it claims is merely to make the room which cannot be left by metaphysical realism for the Copernican move.

The other two necessary conditions will be expounded in the following two sections.

5.4.2 The Argument from Laws of Nature