Objections to the “Middle Way”

(a)The Insufficiency Objection

Kant repeatedly characterizes the intellectual pre-established harmony system as a “middle way”. This characterization vividly captures the position of Crusius’ system in Kant’s metaphysical spectrum. The intellectual pre-established harmony steers a middle way precisely because it does not commit to the model of “the object makes the representation possible”, nor to the model of

“the representation makes the object possible”. Kant’s discussion of the “middle way” marks an important improvement of Kant’s argument. Essentially, this move takes a previously neglected

107 alternative into account and thereby closes the logical gap in A-Deduction. Therefore, not only could it be viewed as an important, and even indispensable, complementary argument to the A-Deduction, it also changes the landscape of Transcendental Deduction by committing to an entirely new model of grounding that underlies the system of the intellectual pre-established harmony.

In a footnote to §36 of the Prologomena Kant considers the possibility of “a middle way”

represented by Crusius for the first time, and he argues as follows:

Crusius alone knew of a middle way: namely that a spirit who can neither err nor deceive originally implanted these natural laws in us. But, since false principles are often mixed in as well – of which this man’s system itself provides not a few examples – then, with the lack of sure criteria for distinguishing an authentic origin from a spurious one, the use of such a principle looks very precarious, since one can never know for sure what the spirit of truth or the father of lies may have put into us. (AA 4:320f)

Kant’s talk about “the father of lies” is reminiscent of the Cartesian evil demon, and it suggests that Kant intends to introduce something that could play a role in the radical skeptical scenario. On my reading, however, by “the father of lies” Kant does not have in mind anything like that. According to the Cartesian radical skepticism, even our belief in obviously true principles might be a result of the deception by the evil demon. This Cartesian radical skeptical scenario is inescapable for Kant.

Kant’s point is rather that even if all the inborn principles are believed to be true, it leaves undetermined whether it is the father of lies who deceives us. Kant’s argument rests on his previous objection to the arbitrariness of the C-criterion. If all the principles implanted in the human mind are true, it follows that it is the spirit of truth who implants them. If there are some false principles, it follows that we cannot tell whether it is the father of lies or the spirit of truth who implants them.

Given the fact that the C-criterion recruits false principles, it can be inferred from that “false principles are often mixed” that there is a father of lies.

Therefore, it implies that the general role of the implanter of all true principles cannot be individuated into the spirit of truth; and the spirit of truth in turn cannot be individuated into God.

The previous quotation from the Prologomena suggests that it should have taken Kant an additional argument against that only God can play the role of the spirit of truth that implants the rules into human mind by excluding anything else (angle for instance) who can play the role. In the 1787 Critique, however, Kant explicitly identifies “subjective predispositions for thinking” as “implanted in us along with our existence by our author” (B167). So in the following, I will leave aside the second worry of individuation and focus on other objections.

108 (b) The Subjectivity Objection and Causal Realism

A passage on Crusius similar to the above one in the Prologomena appears in the Critique:

(besides the fact that on such a hypothesis no end can be seen to how far one might drive the presupposition of predetermined predispositions for future judgments) this would be decisive against the supposed middle way: that in such a case the categories would lack the necessity that is essential to their concept. For, e.g., the concept of cause, which asserts the necessity of a consequent under a presupposed condition, would be false if it rested only on a subjective necessity, arbitrarily implanted in us, of combining certain empirical representations according to such a rule of relation. I would not be able to say that the effect is combined with the cause in the object (i.e., necessarily), but only that I am so constituted that I cannot think of this representation otherwise than as so connected; which is precisely what the skeptic wishes most, for then all of our insight through the supposed objective validity of our judgments is nothing but sheer illusion, and there would be no shortage of people who would not concede this subjective necessity (which must be felt) on their own; at least one would not be able to quarrel with anyone about that which merely depends on the way in which his subject is organized. (B167-168)

Many texts in the 1787 Critique could find precedents in Prologomena, and in most cases the former is merely a repetition of the latter. However, this passage is an exception. While this passage serves also as a criticism against Crusius, it develops an entirely new argument, and Kant even calls it the “most decisive”. This most decisive objection appears to be that “the categories would lack the necessity that is essential to their concept”. Kant’s following explication reads: “I would not be able to say that the effect is combined with the cause in the object (i.e., necessarily), but only that I am so constituted that I cannot think of this representation otherwise than as so connected” (B168).

In effect, Kant draws a distinction between two kinds of necessity: objective necessity and subjective necessity. At first, Kant’s reproach of subjective necessity is perplexing; we have been accustomed to the view that Kant’s objectivity is nothing but the necessity initiated by subject. If there is another kind of subjective necessity, the difference between Kant and Crusius seems too nuanced to be detected. As Kant makes it clear, however, the distinction between subject necessity and objective necessity is clear-cut: the former concerns the constitution, or the predisposition, of the human mind, while the latter is the combination in the object.

Kant’s objection is that if we adopt the Crusian preformation system, then we would not have objective representation at all. Since what is taken under consideration are innate concepts which are a priori, it amounts to saying that we would not have objective a priori concepts. This is not the only way to understand Kant’s point in his objection. Kant’s objection could make sense without

109 committing to the premise (2). According to this interpretation, Kant’s objection is that the conception of the innate objective representation is simply conceptually incoherent.

According to the traditional conception of objectivity, a representation r is objective iff r is correspondent to the object o outside r. According to this conception of objectivity, it is unobjectionable that the Crusian innate concepts and principles are objective. However, Kant rejects such a traditional conception of objectivity in favor of a new and stronger conception of objectivity: an a priori representation r is objective if and only if (i) it is instantiated in experience, and (ii) its instantiation is really grounded on the a priori representation in question.

It becomes apparent that the parallelism or isomorphism in the agreement is too weak to be adequate for objectivity, so Kant introduces new conditions to modify the old conception of the objectivity of representation. The new condition (ii) is a requirement of Kant’s assumption of explanatory rationalism, which is intended to forestall the occult quality objection, which is the innate version of the Crusian system. For Kant, a purely contingent agreement cannot yield objectivity at all.

The condition (ii) not only says that there should be a ground but also says that the ground should be real. Therefore, it betrays that in addition to the explanatory rationalism, the causal realism is also brought in play in his conception of objectivity. According to causal realism, a ground g is real if and only if g is non-ideal, that is, non-reductive.¹⁴⁴ For instance, in a series of causal events, a causes b, and b causes c, then a is an ideal cause of c. In the example, a does not really cause c, for it could be reduced into two causal events that a causes b and that b causes c.¹⁴⁵ Likewise, the common cause model falls short of constituting real grounding between the two parallel series. The consequence of Kant’s causal realism is profound. It does not only preclude the purely contingent agreement between two things. It also excludes a kind of hypothetically necessary agreement.

Therefore, both the innateness version and implantation version of the Crusian system are rejected.

Kant observes that the Crusian preformation system converges with skepticism. This remark is surprising. As is well known, skepticism is Kant’s standard label on Hume. As a classical rationalist, Crusius insists that a priori concepts are innate and implanted by God. As a classical empiricist, by contrast, Hume believes that all concepts are derived from experience. The difference between a classical rationalist and a classical empiricist is even huger than their difference from Kant. How should we make sense of Kant’s charge of skepticism? Here Kant explains the derivation of a priori concepts from experience in terms of “from a subjective necessity arisen from

144 For Leibniz’s notion of ideality as reductivity see Langton 1998.

145 Leibniz discusses the conception of ideal influence in his The Monadology. See Leibniz 1989, 219.

110 frequent association in experience, which is subsequently falsely held to be objective, i.e., custom”

(B127). While for nativist the subjective necessity is endowed by God, for empiricist subjective necessity is acquired by frequent association.¹⁴⁶ It is clear that for Kant what Hume and Crusius have in common is the fact that both of them could only reach subjective necessity. Subjective necessity is simply a matter of how mind behaves without reference to how the objects are and how they could be related to the mental representations. What is at play in Kant’s criticism is still Kant’s characteristic conception of objectivity.