The Evolution of Modern Metaphysics: Making Sense of Things (10 page)

You may already be taken aback. Have I not just contradicted two of the best-known facts about Descartes’ philosophy? Surely, in his very method of doubt, he showed that there was no truth that he took to be beyond doubt, or no necessary truth.
¹
And did he not famously insist that both the truth and the necessity of any necessary truth depend on God’s free choice?

I admit that I have opened this chapter in a deliberately provocative way. I do not deny either of these familiar facts, and in due course I must explain how I reconcile my opening claims with them. But I have begun in this way not just to be provocative, but also to highlight what seem to me crucial features of Descartes’ conception of metaphysics. Descartes was committed to the pursuit of truth, in the form of the pursuit of scientific knowledge or
scientia
.
²
We might equally say, he was committed to the attempt to make sense of things – on one good interpretation of that phrase. The
most general
attempt to make sense of things is an integral part of this. It involves taking a reflective step back, and enquiring self-consciously into the nature of the
enterprise as a whole, that is into the nature of the very attempt to make sense of things. Its aim might be, and in Descartes’ case was, to provide a systematic reconstruction of the methods used in the enterprise, vindicating its claims to succeed in doing what it is an attempt to do. And this requires reflection on what it would be to succeed in that respect, on what it would be, in other words, to make sense of things. Such reflection fulfils its function, in Descartes’ view, because it involves careful attention to indubitable truths – if they were not indubitable, metaphysics would stall at the point at which they were being attended to – and because the truths in question are truths about how things must be, in the strongest sense of ‘must’ – if they were truths only about how things must be in a weaker sense of ‘must’, they would not be indubitable.
³
Hence my opening claims.

2. The Nature of the Project: Metaphysics as Providing Science with Foundations

Before I expand on these claims, and on how I propose to reconcile them with the two exegetical facts that are supposed to tell against them, I need to say some more about Descartes’ overall project and the context within which it arises.

Descartes is often said to be, among philosophers, the first great modern. That is entirely apt. But there would also be some justice in calling him the last great scholastic. He shares many of the concerns, attitudes, and basic methodological tools of that distinctive combination of Aristotelianism and Christianity which dominated European thought in the previous four centuries. Here are some notable examples, to which we shall return. He retains

• a conviction that knowledge is capable of forming a systematically interrelated whole, in other words a conviction that it is possible to make unified sense of things (e.g.
Rule One
)

• the idea of substance and much of the apparatus that goes with it, including a distinction between corporeal substance and incorporeal substance (e.g.
Sixth Meditation
)

and

• the principle that ‘there must be at least as much reality in the efficient and total cause as in the effect of that cause’ (
Meditations
, VII: 40).

True, there are issues about the extent to which he merely shares a vocabulary with his predecessors and the extent to which he also shares an understanding of that vocabulary. For instance, he offers his own definition of substance (which we shall consider in §6) and he insists, in opposition to mainstream scholasticism, that God alone is a substance in the strictest sense – though he also recognizes created substances in a less strict sense. But there is no denying that he draws on his heritage in ways that are both crucial in shaping his own philosophical system and, from the perspective of contemporary philosophy, more or less alien.
⁴

What earns him the title ‘the first great modern’ then? Perhaps, more than anything else, a preparedness to reflect critically on his heritage and to ask, using no other resources than are available from that position of critical reflection, what
entitles
him to draw on his heritage in the ways in which he does; a preparedness to question all authority except for that of his own reason, his own faculty for ‘clear and evident intuition’ and the ‘certain deduction’ of its consequences (
Rules
, X: 366).
⁵
One effect of this is an accentuation of epistemology, the study of knowledge, in the overall attempt to make sense of things. Descartes seeks not merely to know, but to know that he knows, and, as a means to that end, to know what it is for him to know. If we find it puzzling that he nevertheless accepts, seemingly uncritically, so much of what we find unacceptable, then we are probably overlooking both the extent to which thinking in general, not just Descartes’ thinking, is determined by its historical and cultural context and the extent to which what we find unacceptable is in any case, ironically, a long-term effect of Descartes’ own iconoclasm.

Descartes’ critical step back leads, as I suggested in §1, to reflection on the very idea of making sense of things and on the means to that end. Since such reflection is itself part of the attempt to make sense of things, we can see Descartes as aspiring to a single self-contained conception that will help to explain how we are able to achieve that very conception. The conception itself is to be pursued largely for its own sake. Descartes’ project is, to echo the celebrated subtitle of Bernard Williams’ book on him (Williams (
1978
)), a project of pure enquiry. Not that this flouts any of my reservations, aired in §7 of the Introduction, about pursuing
metaphysics
for its own sake.
⁶
If those reservations are justified, then metaphysics, the most general attempt to make sense of things, should subserve the overall attempt to make sense
of things; but this leaves open the possibility that the latter can be pursued for its own sake. For Descartes, the former does indeed subserve the latter. Metaphysics plays a
foundational
role in the overall endeavour. In a well-known passage from the Preface to the French edition of his
Principles
he writes:

The whole of philosophy is like a tree. The roots are metaphysics, the trunk is physics, and the branches emerging from the trunk are all the other sciences. (IXB: 14)
⁷

This idea that metaphysics should be in the service of science has recurred in various guises right through to the present day, where it still has many adherents. What is far less common nowadays is the belief that this service should take the form of providing foundations. One currently popular view, deriving from Wittgenstein, is that metaphysics (as I am construing it) is something of an altogether different kind from science, a search for clarity of understanding rather than a search for truth, which is nevertheless capable of assisting science because scientific concepts themselves need to be clearly understood. Another currently popular view, fundamentally opposed to that and associated particularly with Quine, is that metaphysics is entirely of a piece with (the rest of) science, save only for its generality; in particular, it is as much supported by it as supportive of it.
⁸
In neither case is
metaphysics reckoned to provide science with foundations. Descartes’ view of metaphysics – as a kind of propaedeutic to science, designed to vindicate it and thereby to enable it to be pursued in its own terms, with its own clear rationale, and in good faith – is in that respect decidedly outdated, a lineament, as it now appears, of early modernity.

There is perhaps no clearer indication of Descartes’ own deep commitment to this view than his claim that this most general attempt to make sense of things can be made, and should be made,
once for all
. (That sounds very uncongenial to most contemporary ears.) As he says in the opening sentences of his
Meditations
:

Some years ago I was struck by the large number of falsehoods that I had accepted as true in my childhood, and by the highly doubtful nature of the whole edifice that I had subsequently based on them. I realized that it was necessary,
once in the course of my life
, to demolish everything completely and start again right from the foundations if I wanted to establish anything at all in the sciences that was stable and likely to last. (VII: 17, emphasis added)

3. The Execution of the Project

Something that is ‘stable and likely to last’ is something that can withstand any sceptical attack. Descartes is preemptive. He assumes the role of arch-sceptic. He doubts everything. This is precisely in order to see whether there is anything that cannot be doubted, anything that can somehow be used to rebut his own universal doubt. If there is, then it is fit to serve as a foundation for science. For whatever survives his own assault can survive the assault of a genuine sceptic.

But surely Descartes’ strategy is self-stultifying? If he doubts everything, then does it not follow, as a matter of simple logic, that there is nothing that cannot be doubted (
ab esse ad posse
)?

It follows only if the antecedent and the consequent here are understood as standing in a suitable relation of ‘
esse
’ and ‘
posse
’ to each other. There are two ways in which Descartes could deny that this is how they are to be understood. First, he could say that ‘doubt’ means different things in the antecedent and the consequent, for example ‘call into question’ and ‘regard as a genuine candidate for falsity’, respectively. This is a less promising response than it looks, however. To be sure, there is a distinction between merely asking whether something might be false and asserting, thinking, or supposing that it might. But Descartes’ universal doubt is not purely interrogative. If it is to be characterized as calling everything into question, then calling a thing into question had better involve
some
commitment to the possibility that that thing is false. But how in that case does calling a thing into question fall short of ‘regarding’ it as ‘a genuine candidate’ for falsity?
It is not at all clear that there is any relevant substantive distinction to be drawn between these.

More promising, it seems to me, and more in keeping with how Descartes in fact conceives his strategy, is the second available response: to focus on relativization in the notion of possibility.
⁹
Consider: there is an obvious and clear sense in which somebody’s actually moving his rook diagonally in a game of chess is no proof that he can do so, the sense in which the possibility in question is relative to the rules of chess.
¹⁰
Likewise, I suggest, in the Cartesian case, where there is relativization to giving full attention to the matter in question. Thus what I can doubt when I prescind from an issue and reflect in general terms on whether I might be mistaken in my beliefs is different from what I can doubt when I give my full attention to the issue. Perhaps, from that position of general reflection, I can doubt that one plus two is three, say on the grounds that I might have been brainwashed into thinking that it is, whereas when I focus on the mathematical issue itself I can no longer doubt (see e.g.
Meditations
, VII: 35–36).
¹¹

This, incidentally, is how I reconcile my opening claim in this chapter with the first of the two items of common exegetical knowledge. Yes, Descartes adopts a method of doubt which shows that he takes nothing to be beyond doubt
¹²
from the relevant position of general reflection. No, he does not believe that each thing remains beyond doubt when full attention is given to it.

But does the indubitability of specific beliefs, when full attention is given to them, provide Descartes with the secure foundation that he requires? Surely, their dubitability from the position of general reflection is enough for them to be vulnerable to sceptical attack? From that position a sceptic can always ask, ‘Why should the fact that I cannot doubt something, when I give it my full attention, mean that it is true?’ Call this question the Reflective Question.

The concern implicit in the Reflective Question bears striking witness to the tension between self-consciousness and self-confidence to which I referred in §5 of the Introduction. Descartes is fully aware of this concern
(e.g.
Meditations
, VII: 36). As part of his response to it he provides his own account of what it is to give something one’s full attention. He talks in terms of ‘clear and distinct perception’. Roughly, to perceive something clearly is simply to attend to it; to perceive something distinctly is, in addition, to attend to every aspect of it, thereby ensuring that the perception is not confused with any other (
Principles
, Pt One, §§45 and 46).
¹³
Note that there are two requirements that the notion needs to satisfy if it is to play the foundational rôle that it is supposed to play for Descartes, and if he is to stand any chance of providing a satisfactory answer to the Reflective Question. The first requirement is that it should be possible for whoever clearly and distinctly perceives something to be true to tell this introspectively. In particular, such a person has to be able to tell this without yet being able to tell whether the thing in question is in fact true. This means that ‘clearly and distinctly perceives to be true’ must not be understood (as ‘knows to be true’ is understood) in such a way that, by definition, it cannot relate a person to a falsehood (cf.
Discourse
, VI: 38–39 and
Meditations
, VII: 35 and 62
¹⁴
). The second requirement is that there should be a normative dimension to the notion. Being convinced that something is true when one is in no fit state to have a view on the matter, for example when one has been drugged or when one is suffering from some kind of delirium, had better not count as clearly and distinctly perceiving it to be true (cf.
Replies
, VII: 461–462). The first requirement is so that clear and distinct perception be
serviceable
in founding science; the second requirement is so that it be
effective
in doing so. The obvious problem, which I here simply note, is that the two requirements are in tension with each other. Be that as it may, the Reflective Question can now be formulated as follows.