The Evolution of Modern Metaphysics: Making Sense of Things (32 page)

But it is impossible to remove the offending assumption without disentangling the two elements in the confused concept of the physical universe as a whole, and therefore without distinguishing between physical things and things in themselves; in other words without regarding physical things as mere appearances; or in yet other words without accepting transcendental idealism. Kant accordingly regards this dialectic as providing further support for transcendental idealism. He writes:

One can … draw from this antinomy a true utility …, namely that of … proving indirectly the transcendental ideality of appearances…. The proof would consist in this dilemma. If the world is a whole existing in itself, then it is either finite or infinite. Now the first as well as the second alternative is false (according to the proof offered above for the antithesis [sc. that the world is infinite] on the one side and the thesis [sc. that the world is finite] on the other). Thus it is also false that the world (the sum total of all appearances) is a whole existing in itself. From which it follows that appearances in general are nothing outside our representations, which is just what we mean by their transcendental ideality. (A506–507/B534–535; cf. Bxx and
Prolegomena
, 4:341, n.)

Not that removing the offending assumption prevents the arguments in question from continuing to impress themselves upon us. Kant believes that he is dealing with an irresistible illusion which, like an optical illusion, survives our knowledge that that is what it is. And we are all subject to it. It is
utterly natural.
⁵¹
True, Kant’s concern is with errors perpetrated by metaphysicians. But we are all, to some extent, metaphysicians (cf.
Prolegomena
, 4:367). Kant writes:

Transcendental illusion … does not cease even though it is uncovered and its nullity is clearly seen into by transcendental criticism (e.g. the illusion in the proposition: ‘The world must have a beginning in time’)…. [This is] an
illusion
that cannot be avoided at all, just as little as we can avoid it that the sea appears higher in the middle than at the shores, since we see the former through higher rays of light than the latter, or even better, just as little as the astronomer can prevent the rising moon from appearing larger to him, even when he is not deceived by this illusion. (A297/B353–354, emphasis in original)

There are various senses of irresistibility in which it is irresistible for us to form judgments in response to the well-conceived questions too.
⁵²
Indeed, there is a sense, albeit superficial enough to allow for the many unbelievers who have reflected on these questions, in which we have no choice but to believe that God exists and that we are immortal. (I shall say more about this in the next section.) There is an altogether more profound sense in which we have no choice but to believe that we have free will. ‘The will of [a rational] being,’ Kant contends, ‘cannot be a will of his own except under the idea of freedom’ (
Groundwork
, 4:448, emphasis added; cf. 2nd
Critique
, 5:30–31 and 103ff.). It remains the case that we cannot prove any of these things. Kant considers and rejects purported proofs of them, much as he did the arguments concerning the ill-conceived questions.
⁵³
By the end of the ‘Transcendental Dialectic’ his assault on what he sees as bad metaphysics is complete. And it far exceeds, in destructive power, in diagnostic power, and in systematicity, anything that we saw in Hume.
⁵⁴

7. The Regulative Use of Concepts

Yet even in the ambitions of bad metaphysics there is something that Kant sees fit to salvage. Moreover, what he sees fit to salvage may yet count, on a relaxed, non-epistemic interpretation of what it is to make sense of something, as bona fide sense-making. Indeed, granted the high level of generality at which Kant is operating, it may yet count, on the broad conception of metaphysics that I have adopted, as good metaphysics.

Kant distinguishes between a
constitutive
use of a concept and a
regulative
use of a concept. A constitutive use of a concept is a use of it in representing things to be a certain way. A regulative use of a concept is a use of it in framing a rule, what Kant would call a ‘regulative principle’, enjoining us to proceed
as if
things were a certain way. What the ‘Transcendental Dialectic’ shows is that certain constitutive uses of concepts are illegitimate, either because the concepts conflate ideas of reason with concepts applicable only to objects of possible experience, and the questions being addressed are ill-conceived, or because the concepts are undistorted ideas of reason, and the questions being addressed, though they are well-conceived, are questions that we have no way of answering: we have no way of knowing where, if at all, these concepts are instantiated. It does not follow from the fact that some constitutive use of a concept is illegitimate in either of these two ways – not even the first, where the concept is confused – that the corresponding regulative use is illegitimate. It is Kant’s conviction that there are many such regulative uses of concepts that are quite legitimate (A644–645/B672–673 and A669/B697ff.).
⁵⁵
And these are precisely what he wishes to salvage and to champion.

Thus the concept of the physical universe as a whole has in Kant’s view a legitimate regulative use: to enjoin us to proceed as if the physical universe existed as an infinite whole, and thus never to give up in our quest for a deeper and more extensive understanding of nature, no matter how much we have already explored (A508–515/B536–543). He likewise believes that there are legitimate regulative uses of undistorted ideas of reason. Reconsider the three concepts of God, freedom, and immortality. Kant calls the three propositions stating that these concepts are instantiated among things in themselves ‘postulates of pure practical reason’. Although we can never know whether these postulates are true, it is Kant’s conviction that they can serve as vital regulative principles. That is, each of the three concepts has a vital regulative use: to enjoin us to proceed as if it were indeed instantiated among things in themselves (see e.g. 2nd
Critique
, 5:48–49; 3rd
Critique
, §76; and
Religion
, 6:71 n.).

Why should we proceed thus? Why should we make sense of things in
these
highly distinctive, totally unfounded ways? Well, as I remarked in the previous section, there is a sense, for Kant, in which we have no choice but to do so. This sense is profound where our own freedom is concerned. But our freedom carries with it certain demands: demands of rational action; demands, as Kant sees it, of morality. And he believes that, because of our imperfection, we cannot sustain a commitment to these demands without the aid of certain non-rational props. These include certain hopes. They include the hope that, imperfect as we are, we have scope to reform, and, as a corollary, that we enjoy an immortality that will enable us to work out our reformation. They also include the hope that virtue and happiness are somehow ultimately aligned, which in turn requires the hope that God, who alone is able to guarantee such an alignment, exists.
⁵⁶
We need to make sense of things in these ways if we are to make real, practical sense of freedom itself, along with its various demands. We need to hope that the world is a
home
for such practical sense-making, that the world itself, to that extent, makes sense.
⁵⁷

It is precisely because we cherish these hopes, Kant suggests, that metaphysicians have such a keen interest in these issues (
Prolegomena
, §60). In the first
Critique
he proclaims:

All interest of my reason … is united in the following three questions.

1.
What can I know?

2.
What should I do?

3.
What may I hope?

(A804–805/B832–833, emphasis in original)

Bad, transcendent metaphysics is at root an attempt to provide reassurance concerning the third of these questions (
Prolegomena
, §60). But it is an attempt to do more than that. It is an attempt, ironically, to eliminate the very need for hope, by actually establishing the three propositions in question, the three postulates of pure practical reason. The urge not merely to protect these postulates, but to establish them, is an understandable reaction to the very real and very severe threats they face. These threats emanate most directly from natural science, especially in its Newtonian guise, whereby everything in nature seems to be governed by inexorable mechanical laws, laws that already preclude the hope that gives every other hope its rationale, namely that we are free. If we are not free, morality itself makes
no sense (A468/B496) and all the props that we use to sustain our commitment to morality are a sad mockery. Moreover, these threats are exacerbated by Kant’s own proof of the Causal Principle – as he is well aware.
⁵⁸

Kant is nevertheless able to sidestep these threats. By insisting that our hopes concern how things are in themselves, and in particular that whether we are free or not is a matter of how we are in ourselves, he can afford to be insouciant both about the Causal Principle and about any of the findings of natural science, whose domain is the physical world, the world of appearances (Bxxvi–xxx).
⁵⁹
The fact that our hopes cannot be established therefore begins to look like a mixed curse. For, by precisely the same token, they cannot be refuted either (A753/781). The form that Kant gives to the third of his questions – ‘What
may
I hope?’ – is thus entirely apt. Protection of our hopes is as much as is available to us: it is also as much as we need. The whole complex machinery that drives Kant’s transcendental idealism, with its curbing of our attempts to answer the great questions of metaphysics, in fact serves to keep our most important hopes alive. ‘I had to deny
knowledge
,’ Kant famously declares in the Preface to the second edition of the first
Critique
, ‘in order to make room for
faith
’ (Bxxx, his emphasis).
⁶⁰
Of all the great reconciling projects undertaken both in the first
Critique
and elsewhere in Kant’s work (see §1), that between the demands of Christian morality and the demands of Newtonian mechanics is the most important,
the most profound, and the one to which Kant is most ardently committed (A797–801/B825–829).
⁶¹

8. Thick Sense-Making and Thin Sense-Making

In this section I want to reflect on three interrelated questions that arise within Kant’s system. What can we know about things in themselves? What can we think about things in themselves? What is the importance of this distinction for Kant’s metaphysics? (The importance of the distinction for sustaining our commitment to the demands of our own freedom has been one of the main burdens of the previous section, and I shall take that as read.)

Concerning the question of what we can know about things in themselves, the answer is not nothing. Kant does not deny that we can have analytic knowledge about things in themselves (see e.g. A258–259/B314–315).
⁶²
Hence he does not pick any quarrel with metaphysicians when they apply the laws of logic in their abortive attempts to engage in transcendent metaphysics, whatever other quarrels he might pick, and he himself makes free use of such laws, in application to the transcendent, when rebutting them (see e.g. A502/B530ff. and A571/B599ff.).
⁶³

It would make for an easy exegetical life if we could say that what Kant denies us is synthetic knowledge about things in themselves. And indeed I have already represented him in just these terms. But there is an issue about the very knowledge that there
are
things in themselves, which Kant seems to grant us, referring at one point to ‘the absurd proposition that there is an appearance without anything that appears’ (Bxxvi; cf. A696/B724 and
Prolegomena
, 4:350–351).
⁶⁴
He also seems to grant us knowledge about some of the things
that things in themselves are
not
, notably spatial or temporal, or for that matter knowable (synthetically, by us). For instance, he writes that

• ‘space represents no property at all of any things in themselves nor any relation of them to each other’ (A26/B42)

that

• ‘[time] cannot be counted either as subsisting or inhering in the objects in themselves’ (A36/B52)

and that

• ‘objects in themselves are not known to us at all.’ (A30/B45)

Are we not reckoned to know
these
things? Or has there perhaps been some tacit restriction, throughout all Kant’s knowledge denials, to knowledge of some privileged and robust kind, knowledge which is not purely existential, say, and which is perhaps positive rather than negative, in some suitable sense of these two terms (cf. B307ff.)?
⁶⁵
(After all, the restriction to synthetic knowledge is often tacit, as in the third bulleted quotation.) Or is it simply that we are beginning to witness cracks in Kant’s edifice? I shall express my own pessimism on that score in the next section.