THE LIMITS OF SENSE AND REASON: A Line-By-Line Critical Commentary on Kant’s “Critique of Pure Reason,” #9–A Preview of the Transcendental Deduction of the Pure Concepts of the Understanding, & The Gap in the Deduction.


[I] was then making plans for a work that might perhaps have the title, “The Limits of Sense and Reason.” I planned to have it consist of two parts, a theoretical and a practical. The first part would have two sections, (1) general phenomenology and (2) metaphysics, but this only with regard to its method. (Letter to Marcus Herz, 21 February 1772 [C 10: 129])



Previous Installments:

#1: Introduction to The Limits of Sense and Reason

#2: Bii/GW91 The Motto

#3: Aiii/Biii/GW93-97 The Dedication

#4: Avii-ix/GW99 Preface to the First (A) Edition.

#5: Axi note/GW100-101 Preface to the First (A) Edition

#6: Axi note/GW100-101 Preface to the First (A) Edition

#7: Axii-xiv/GW101-102 Preface to the First (A) Edition

#8: Axv-xvi/GW102-103 Preface to the First (A) Edition


Because LSR is an ongoing and indeed infinite task, yearly installments of the book will be published in the online journal Contemporary Studies in Kantian Philosophy (CSKP).

Correspondingly, LSR, Part 1 has been published in CSKP 6 (2021): 11-109, and can be read, downloaded, or shared in .pdf HERE.

Moreover, a bibliography of Kant’s writings listed by English translations of their titles, alongside the abbreviations used for infratextual references in LSR, has been also been published in CSKP 6 (2021): 1-10, and can be read, downloaded, or shared in .pdf HERE.


CPR TEXT Axvi-xvii/GW103 Preface to the First (A) Edition

   I am acquainted with no investigations more important for getting to the bottom of that faculty we call the understanding, and at same time for the determination of the rules and boundaries of its use, than those I have undertaken in the second chapter of the Transcendental Analytic, under the title Deduction of the Pure Concepts of the Understanding; they are also the investigations have cost me the most, but I hope not unrewarded, effort. This inquiry, which goes rather deep, has two sides. One side refers to the objects of the pure understanding, and is supposed to demonstrate and make comprehensible the objective validity of its concepts a priori; thus it belongs essentially to my ends. The other side deals with the pure understanding itself, concerning its possibility and the powers of cognition on which it itself rests; thus it considers it in a subjective relation, and although this ex- Axvii -position is of great importance in respect of my chief end, it does not belong essentially to it; because the chief question always remains: “What and how much can understanding and reason cognize free of all experience?” and not: “How is the faculty of thinking itself possible?” Since the latter question is something like the search for the cause of a given effect, and is therefore something like a hypothesis (although, as I will elsewhere take the opportunity to show, this is not in fact how matters stand), it appears as if I am taking the liberty in this case of expressing an opinion, and that the reader might therefore be free to another opinion. In view of this I must remind reader in advance that even in case my subjective deduction does not produce complete conviction that I expect, the objective deduction that is my primary concern would come into its full strength, on which what is said at pages [A] 92-3 should even be sufficient by itself.

***

COMMENTARY

Significantly, [Kant] flags the second chapter of the Transcendental Analytic, the “Deduction of the Pure Concepts of the Understanding,” aka the Deduction [, as a target for some worries about whether his arguments have achieved a priori certainty.]

We know from Kant’s own testimony here in the A Preface that the argument spelled out in the Deduction chapter was the most difficult part of the project for him to formulate.

We also know from other biographical sources that he repeatedly re-worked and re-wrote the Deduction during the decade prior to CPR’s publication.

So we can reasonably conclude that the difficulty Kant encountered in formulating the Deduction was the principal reason it took him so long to finish the book.

We also know that the Deduction was almost universally either seriously misunderstood or regarded as hopelessly obscure, by readers of the A edition, so that Kant yet again completely re-wrote it for the B edition.

It’s true that the B Deduction is clearer and easier to follow.

Unfortunately, however, most readers of the CPR since 1787 have had pretty much the same pair of alternative reactions to the B Deduction that the original readers of the A edition had to the A Deduction: either seriously  misunderstanding it or recoiling from its rebarbative obscurity.

But from our own late 20th or early 21st century point of view, sadly, the interpretive situation with respect to the Deduction is even worse.

One important, enduring problem for recent and contemporary English-speaking readers is that the term “deduction” or Deduktion, as Kant uses it, does not mean what the contemporary logico-philosophical technical term “deduction” means, namely a formally valid or sound proof of some proposition, the conclusion, from another set of propositions, the premises.

The 18th century German term that comes closest to meaning what the contemporary technical term “deduction” means is Vernunftschluss or “inference of reason.”

By contrast, the term “deduction,” as Kant employs it, is in fact an 18th century legal term which means, roughly, this:

an argument that justifies, from pre-existing juridical principles, hence de jure, some or another claim about keeping and using something that’s already in one’s own possession, as a matter of fact, hence de facto.

Now “concepts” for Kant are essentially general mental representations or cognitive devices of description.

“Pure” representations are those representations that contain no empirical content whatsoever, and whose semantic contents are underdetermined by all actual or possible sensory experiences and/or contingent facts (= apriority), that is, whose semantic contents are necessarily underdetermined by sensory experiences and/or contingent facts.

And “concepts of the understanding” are concepts that are intrinsic to, or innately specified within, the cognitive faculty of understanding or Verstand.

Granting those notions as background assumptions, and reduced to its bare essentials, the goal of the Deduction of the Pure Concepts of the Understanding is this:

to demonstrate that our rational human experience of manifestly real, authentically apparent, or phenomenal objects in the empirically real natural world is really possible if and only if the complete and unique set of all pure concepts of the understanding is necessarily presupposed by that experience.

In turn, this result suffices to show that the pure concepts of the understanding are empirically meaningful, or “objectively valid,” solely by reference to the manifestly real objects of rational human experience, and not by reference to any supposedly existing Really Real objects, noumena, or things-in-themselves, that, if they were indeed to exist, would transcend rational human experience; and it also thereby demonstrates that our innate possession of the pure concepts is justified by our rational human experience of manifestly real objects alone.

If Kant’s transcendental idealism—which postulates the asymmetric necessary conformity of the spatiotemporal and causal-dynamic structures and relations of the manifestly real natural world to the innately-specified mentalistic structures of rational human cognition—is true, then the Deduction of the Pure Concepts will also suffice to show that the manifestly real objects of rational human sense perception and experience themselves are really possible if and only if the complete and unique set of all pure concepts of the understanding is necessarily presupposed by the rational human sense perception and experience of manifestly real objects.

There’s much, much more to be said about this argument.

For the moment, what’s immediately relevant is that in the A Preface, Kant notoriously asserts that the argument “has two sides.”

One side of the argument refers to the objects of human understanding, and is nowadays dubbed The Objective Deduction.

The other side of the argument refers to the internal structure of the faculty of human understanding itself, and is nowadays dubbed The Subjective Deduction.

That in and of itself isn’t so terribly confusing, since it’s obvious enough even from the very brief gloss of the Deduction I spelled out just above, that the overall argument is as much about manifestly real objects of human experience as it is about the faculty of human understanding by means of which human experience of manifestly real occurs.

Later in LST, I’ll critically explore the perhaps surprising Kantian thesis of the necessary equivalence of human-experience-of-objects and objects-of-human-experience in detail.

But for the moment we need only note that the Deduction presupposes this necessary equivalence, and doesn’t prove it.

What has caused the most difficulty for interpreters of the A Deduction, I think, is Kant’s claim that only The Objective Deduction is essential to the Deduction’s main thesis, and that The Subjective Deduction is not essential to it.

This makes it seem as if The Subjective Deduction is either not required by the overall Deduction or else is somehow irrelevant to the Deduction.

Nevertheless, given Kant’s goal in the overall Deduction, it’s clear that both of these seeming implications are false.

If The Subjective Deduction were either falsified or deleted, then the overall Deduction would be unsound.

What Kant really means, I think, is that the overall Deduction is not primarily intended by him to be a study in the philosophical psychology of the innate structure of the human understanding.

Instead, the overall Deduction is primarily intended by Kant to be a study of the necessary relationship between the innate structure of the human understanding and our objective experience of the manifestly real empirical world, as opposed to our cognition of any supposedly existing Really Real objects that transcend human experience.

That pretty clearly seems to be what he means by this:

[T]he chief question always remains: “What and how much can understanding and reason cognize free of all experience?” and not: “How is the faculty of thinking itself possible?” (CPR Axvii, boldfacing in the original)

The philosophical psychology of the innate structure of the human understanding, Kant thinks, is very likely to be taken by his readers to be a somewhat hypothetical inquiry, as if it were based on an inference from a given existing effect (= human experience of manifestly real objects) to its hypothesized cause (= the innately-specified cognitive faculty for generating human experience).

Kant himself, however, does not actually hold this inference-from-effect-to-cause view about the philosophical psychology of our innate cognitive capacities.

But since it’s the prevailing view in 18th century philosophical psychology, and since it’s not Kant’s basic intention in the overall Deduction to carry out an investigation in innatist philosophical psychology, he says that readers would be better served, and less likely to be skeptical about the overall argument, if they focused primarily on The Objective Deduction and not primarily on The Subjective Deduction.

To be quite frank, sadly, from a presentational standpoint, this way of putting things is a complete mess, and the very opposite of lucid.

In fact, the Subjective Deduction is every bit as as essential to the overall goal of the Deduction, and to its soundness, as The Objective Deduction.

Without a set of well-supported premises taken from the correct innatist philosophical psychology of the human understanding, the argument simply won’t work.

It’s quite true that the overall Deduction of the Pure Concepts of the Understanding is not primarily an investigation in the innatist philosophical psychology of the human understanding.

Still, it necessarily presupposes and inherently incorporates this investigation.

Therefore, it’s not true that The Subjective Deduction is not essential to the Deduction as regards its theoretical content.

Consequently, Kant should never have used the phrase “not essential” (nicht wesentlich) when he really meant something like not methodologically primary; nor should he ever have split the overall argument into two parts.

Not surprisingly, then, in the B edition version of the Deduction, the two sides of the A Deduction, the objective side and the subjective side, are integrated into a single line of argument.

That solves a significant part of the serious-presentational-messiness, or non-lucidity, problem in the A Deduction.

Yet, as we’ll see below, the critical fact remains that some of the well-supported premises taken from the correct innatist philosophical psychology of the human understanding that are strictly required for the soundness of the overall Deduction, appear in the A Deduction but not in the B Deduction.

So certain crucial aspects of the original serious-presentational-messiness, or non-lucidity, of the A Deduction remain in place, even in the B Deduction.

Therefore, this is one centrally significant place in the CPR—and unfortunately it’s not the only one—where Kant really and truly nods.

To be fair, however, from our point of view, it’s quite understandable why Kant is so twisted up about the Deduction.

We’ll remember that the argument for transcendental idealism for sensibility—the asymmetric necessary conformity of the manifestly world to the innately-specifed a priori structures of sensibility, our forms of intuition, the representations of space and time—was in place by 1770, the year of the publication of the Inaugural Dissertation.

If the Deduction of the Categories is sound, then it directly entails transcendental idealism for the understanding: the necessary conformity of the apparent world to the formal a priori stuctures of the understanding, our pure concepts of the understanding, the categories.

But the formulation of this argument took him eleven years (1770 to 1781) plus another six years (1781 to 1787), equals seventeen years altogether, to complete.

Why did it take the all-around most brilliant, profound, and systematic thinker in modern philosophy so long to formulate this one argument?

In my opinion, it’s precisely because it’s in fact impossible for there to be a sound argument for transcendental idealism for the understanding, if we construe it as an argument for the “application of the Categories to objects of the senses in general” (CPR B150), which is what I call the unbounded scope reading of the B Deduction.

Hence, it’s in fact impossible for there to be a sound version of the Transcendental Deduction of the Categories, whether in the A edition, the B edition, or any possible X,Y, or Z edition, according to the unbounded scope reading.

But why is it impossible?

It’s impossible precisely because the cognitive scope of human sensibility with respect to manifest reality, inherently outruns the cognitive scope of human understanding with respect to manifest reality.[i]

Therefore, there will always be actual or really possible manifestly real objects in space and time, directly accessible by means of empirical intuitions and/or the imagination/memory (or feelings/emotions, or desires/volitions), to which the pure concepts of the understanding, and indeed any concepts whatsoever, cannot be applied, and thus the Deduction of the Categories will always fail.

And therefore, it cannot be soundly shown that the categories necessarily apply to all actual and possible objects of the senses, i.e., to all actual and possible authentic appearances.

This inherent mismatch in cognitive scope between the sensibility (and its intuitions, images, memories, feelings, emotions, desires, and volitions) and the understanding (and its concepts, judgments, and theories), with respect to manifest reality, is what I call The Gap in the Deduction, and we will return to it frequently, and to its profound implications for transcendental idealism and the Critical Philosophy.  

Now, the profound implications of The Gap are not what you might initially think, perhaps, namely, that it’s in any way a philosophically bad thing for either transcendental idealism or the Critical Philosophy, that the Deduction of the Categories turns out to be unsound.

As Lewis Carroll’s Tweedledum so rightly says, although in a slightly different connection: contrariwise.

In point of fact, The Gap is a philosophically bad thing only for orthodox Kant-scholars and Kantians who’ve been indoctrinated into believing that there has to be a sound version of the Deduction according to the unbounded scope reading, or bust.

Nevertheless, given the correct understanding of Kant’s deepest philosophical intentions, especially including his lifelong attempt to come to terms with the philosophical implications of modern natural science and to reconcile the metaphysics of nature and the metaphysics of freedom,[ii] then The Gap is not merely a philosophically good thing, it’s the philosophically best thing.[iii]

So as they say in The London Underground: Mind The Gap.

NOTES

[i] See, e.g., R. Hanna, “Kant’s Non-Conceptualism, Rogue Objects, and the Gap in the B Deduction,” International Journal of Philosophical Studies 19 (2011): 397-413; R. Hanna, “Kantian Madness: Blind Intuitions, Essentially Rogue Objects, Nomological Deviance, and Categorial Anarchy,” Contemporary Studies in Kantian Philosophy 1 (2016): 44-64, available online HERE; and R. Hanna, “Kant’s B Deduction, Cognitive Organicism, the Limits of Natural Science, and the Autonomy of Consciousness,” Contemporary Studies in Kantian Philosophy 4 (2019): 29-46, available online HERE.

[ii] Kant’s other deepest philosophical intention is his lifelong attempt to come to terms with the philosophical implications of 18th century radically enlightened free-thinking about religion/theology and politics in the run-up to the French Revolution—e.g., the Spinozism controversy and Rousseau’s writings. My own view is that he evolved from the classical Enlightenment critique of religion/theology and classical neo-Hobbesian liberalism in his pre-Critical and Critical periods, to radically enlightened realistically optimist dignitarian humanism in his post-Critical period. See, e.g., R. Hanna, “Exiting the State and Debunking the State of Nature,” Con-Textos Kantianos 5 (2017), available online at URL = <https://www.con-textoskantianos.net/index.php/revista/article/view/228>; and R. Hanna, “On Rutger Bregman’s Humankind: Optimism For Realists, Or, Neither Hobbes Nor Rousseau,” (Unpublished MS, 2020), available online HERE.

[iii] See esp. Hanna, “Kantian Madness: Blind Intuitions, Essentially Rogue Objects, Nomological Deviance, and Categorial Anarchy.”


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