The Evolution of Modern Metaphysics: Making Sense of Things (12 page)

The similarities between intuition and sensory perception are a crucial part of Descartes’ overall conception, a conception in whose terms he seeks to explain how we are able to achieve that very conception (see §2). If we set aside any scruples that may still be lingering in connection with the extravagant ‘scepticism’ considered at the end of the previous section, then the idea that there is some troubling circularity here begins to look baseless. Consider, as an analogy, the physiology of vision. This is concerned with a variant of the Reflective Question: why is the fact that someone takes her environment to be a certain way, when she enjoys a visual experience, symptomatic of the fact that it is that way? The answer consists of a sophisticated story about ocular irradiation, retinas, and suchlike. We would not
think
to doubt such an answer just on the grounds that physiologists themselves make use of their faculty of sight in arriving at it, for example when looking at eyeballs or when looking at the readings on various instruments in their laboratories.
²⁷

I referred in §2 to the Quinean view that metaphysics is entirely of a piece with (the rest of) science. Part of that view is what Quine himself has famously called ‘naturalized epistemology’. This is a conception of epistemology as ‘contained in natural science,’ so that, in ‘studying how the human subject … projects his physics from his data, … we appreciate that our position in the world is just like his,’ and ‘our very epistemological enterprise, therefore, … is our own … projection from stimulations like those we were meting out to our epistemological subject’ (Quine (
1969b
), p. 83). As I indicated in §2, Descartes’ foundationalism, whereby the scientific story needs to be grounded in an independent metaphysical story, makes him one of Quine’s principal targets, if not the principal target (e.g. Quine (
1960
), pp. 24–25). And yet, ironically, if we prescind from that admittedly profound difference between their conceptions, we see an equally profound similarity in what remains. Descartes too views epistemology as part of his overall conception of the world, a ‘projection’ from clear and distinct perceptions like those he attributes to his epistemological
subject.
²⁸

5. Analogues of Descartes’ Argument for the Existence of God in Contemporary Analytic Philosophy

That Descartes has built a sturdy structure does not of course entail that he has built a structure that is invulnerable to attack. Its real weak spot is the argument for the existence of God. And I shall make no attempt to defend this argument. Even here, however, it is worth pausing to reflect on analogous arguments that command significant respect in contemporary analytic philosophy.
²⁹

These are arguments to the effect that it is impossible to explain the existence of certain beliefs, perhaps even to understand those beliefs, without oneself sharing them and indeed invoking them, or, relatedly, that it is impossible to explain the existence of certain concepts, perhaps even to grasp those concepts, without oneself taking them to have application in reality and indeed having recourse to that very application; in sum, that it is impossible to make sense of certain ways of making sense of things without oneself making sense of things in those ways. This is obviously not in general true. One can explain the widespread belief among children in Father Christmas even if one does not oneself believe in him, perhaps
only
if one does not oneself believe in him. But if these arguments are sound, then such detachment is not always possible. Thus Hilary Putnam has argued that one could not explain our basic belief in the existence of trees, say, except with reference to trees, thereby defying a certain scepticism about ‘the external world’ (Putnam (
1981
),
Ch. 1
).
³⁰
And Barry Stroud has argued that one could not account for our concept of yellowness if, along with certain physicalists, one subscribed to the view that nothing in the world is ‘really’ yellow (Stroud (
2000
)).
³¹
But the most striking example, in the present context, is supplied by Thomas Nagel. It is the most striking example because, like Descartes’ argument, it involves our idea of infinity, albeit, in Nagel’s case, in a mathematical guise. Nagel reflects on our use of reason – ‘a local activity of finite creatures’ (Nagel (
1997
), p. 70) – to arrive at the idea of infinity. And as against those who think that this both can and must
be understood in terms of our finite resources, without appeal to infinity itself, he urges:

To get [the idea of infinity] we need to be operating with the concept of numbers as the sizes of sets, which can have anything whatever as their elements. What we understand, then, is that the numbers we use to count things … are merely the first part of a series that never ends.

… Though our direct acquaintance with and designation of specific numbers is extremely limited, we cannot
make sense
of it except by putting them, and ourselves, in the context of something larger, something whose existence is independent of our fragmentary experience of it…. When we think about the finite activity of counting, we come to realize that it can only be understood as part of something infinite. (Nagel (
1997
), p. 71, emphasis added)

This is really not so different from what we find in Descartes.
³²

Nevertheless, it is different. And it is different in one crucial respect.
³³
Descartes’ idea of infinity is not primarily mathematical. That is, it is not primarily a matter of the unending (cf. ‘Letter to Clerselier’, dated 23 April 1649, in
Correspondence
, V: 356). It is part of his idea of God. And it has, under that more metaphysical guise, an evaluative aspect: it entails God’s benevolence. So there is far more room for doubt about whether this style of argument can apply to it. We routinely make sense of evaluative ways of making sense of things without endorsing them, and certainly without taking the values in question to be realized.
³⁴

There is a related problem for Descartes. Just as his idea’s evaluative aspect raises concerns about his argument, so too, ironically, it raises concerns about his perceived need for any such argument. For the significance of this evaluative aspect, in terms of Descartes’ overall project, is its relation to his hope that, when he does all that is within his power to avoid error, he shall avoid it. More specifically, Descartes hopes that, when he does all that is within his power to avoid
metaphysical
error, he shall avoid it. And the very fact that this arises for Descartes
as a hope
– the fact that he sees a logical gap between how he takes things to be, when he tries his best
to make the most general sense of them, and how they really are – must cast doubt on his claim to have made sense of
how he takes things to be
. Consider, for example, the fact that, by his own reckoning, he has a clear and distinct perception that he cannot think without existing. If this perception is answerable to a completely independent reality, and if, granted the perception’s high level of generality, such answerability does not involve any direct causal relation between him and that reality, then it is a real question what makes this perception a perception
that he cannot think without existing
. In what relation does this perception stand to the ‘fact’ that he cannot think without existing, but not to the ‘fact’ that one plus two is three, say? This concern, which admittedly merits a far fuller and far less schematic discussion than the little I have said here, is part of my own reason for answering the Creativity Question, from §6 of the Introduction, in such a non-Cartesian way, that is, for insisting that metaphysics is a fundamentally creative exercise.
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6. ‘The Disenchantment of the World’

The logical gap between metaphysical belief and metaphysical reality is not the only logical gap that Descartes acknowledges. He also acknowledges a logical gap between mind and matter. This is in part because, at the point where he first registers the indubitability of his own existence, he takes the existence of material objects to remain in doubt – perhaps he is in the throes of some interminable dream – and concludes that he himself is not a material object (
Meditations
, VII: 26–27). Rather, he is a thinking being, or a mind, and his body, although it is ‘very closely joined’ to him, is nevertheless independent of him (
Meditations
, VII: 78). This connects with Descartes’ views about substance. Substance, on Descartes’ definition, is ‘a thing which exists in such a way as to depend on no other thing whatsoever’ (
Principles
, Pt One, §51). He recognizes three kinds of substance. The first is Divine substance, of which there is only one instance, namely God Himself. As I commented in §2, Descartes takes God to be the only substance in the strictest sense, for everything else is created and sustained by Him and is therefore dependent for its existence on Him. Nonetheless, Descartes also sees an independence among created things, which allows him to recognize two further kinds of substance in a less strict sense. One of these is material substance, or corporeal substance, of which again there is only one instance, an infinite homogeneous fluid that is ultimately no different from
space (
Principles
,
Pt Two
, §11). The second is created thinking substance, of which there are milliards of instances, perhaps even infinitely many, including Descartes himself, you, and me.
³⁶

One consequence of this complicated scheme is that, on at least one reasonable way of construing ‘transcendence’, Descartes allows us scope, within metaphysics, to make sense of what is transcendent (see the Transcendence Question in §6 of the Introduction). An obvious case in point is when we engage in reflection on God. Note, however, that there is just as much rationale within Descartes’ scheme, if not more, for saying that we are making sense of what is transcendent when we engage in geometry or physics. Such is the gap between mind and matter. For this reason among countless others the scheme has had little lasting appeal. In the next two chapters we shall see recoils of particular note on the part of Spinoza and Leibniz.
³⁷

Nevertheless, the indirect influence of the scheme has been immense. It relates to what is perhaps Descartes’ most significant legacy, and what is certainly a highly distinctive feature of the modernity that he helped to inaugurate: a dislocation of the self, or at least of the subjectivity of the self, from the objectivity of its physical surrounds. If this can indeed be said to be Descartes’ most significant legacy, then it can be said to be so only
malgré lui
. For, as I have tried to emphasize in this chapter, Descartes’ vision is a profoundly synoptic one. The problem is that it is also a profoundly self-conscious one, and self-consciousness is always liable to make the environment appear alien. The self, in Descartes’ vision, is autonomous. It is to be conceived independently of its environment, and it directs itself independently of its environment, despite the elaborate story that Descartes tells about how each affects the other and about how the one can know the other (e.g.
Sixth Meditation
).
³⁸
The environment is in turn, and by the same token, to be conceived independently of the self, indeed independently of all intentionality or purpose. The interaction of physical objects – which are parts of the one infinite corporeal substance, and which are distinguished from one another by their relative motion (
Principles
, Pt Two, §23) – is to be explained in a strictly mechanistic way, in terms of the objects’ spatio-temporal properties (
Principles
, Pt Four, §200).
³⁹
This is in opposition to the prevailing
Aristotelianism of Descartes’ day, whereby different sorts of physical object have different ‘forms’ which explain their interaction teleologically. It is in this revolt against Aristotelianism that we see part of what has come to be known, in a phrase due to Max Weber, as ‘the disenchantment of the world’ (Weber (
1946
), p. 155).

Here is the self, then, and there is the ‘transcendent’ world beyond the self, each independent of the other. And for the former to make sense of the latter, on the full Cartesian conception, is for the former to have clear and distinct perceptions, which answer correctly to how the latter is, and then to deduce their consequences. It is for the former to
represent
the latter.

I have already expressed reservations, at the end of the previous section, about whether we can make sense of this relation of representation at the highest level of generality. Because of the role that God plays in Descartes’ system, these must in turn become reservations about whether we can make sense of the relation at any lower level either.
⁴⁰
A fortiori
they must become reservations about whether we can actually stand in this relation to anything, let alone knowingly do so, as Descartes requires. It is not just that there is room for suspicion about whether science can be given metaphysical foundations of the sort that Descartes describes, or about whether it needs them. There is room for suspicion of a much deeper kind, about the very idea of (Cartesian) representation.