FOCUS ON MATERIALISM

WHY I FOCUS ON MATERIALISM

The reason I am going to focus my attack on materialism is that materialism is the only metaphysical picture that has contemporary “clout”. Metaphysics, or the enterprise of describing the “furniture of the world”, the “things in themselves” apart from our conceptual imposition, has been rejected by many analytic philosophers (though not, as I remarked, by Russell), and by all the leading brands of continental philosophy. Today, apart from relics, it is virtually only materialists (or “physicalists”, as they like to call themselves) who continue the traditional enterprise.

It was not always thus. Between the tenth and twelfth centuries the metaphysical community which included the Arabic Averroes and Avicenna, the Jewish Maimonides, and the Angelic Doctor in Paris disagreed on many questions, creation in particular. It was regarded as a hard issue whether the world always existed obeying the same laws (the doctrine ascribed to Aristotle), or was created from pre-existing matter (the doctrine ascribed to Plato) or was created ex nihilo (the Scriptural doctrine). But the existence of a supersensible Cause of the contingent and moving sensible things was taken to be demonstrable . Speculative reason could know there was an Uncaused Cause.

When I was seven years old the question “If God made the world, then who made God?” struck me one evening with vivid force. I remember pacing in circles around a little well for hours while the awful regress played itself out in my mind. If a medieval theologian had been handy, he would have told me that

236 HILARY PUTNAM God’s “necessary” existence invokes a notion of “necessity” which is incoherent

or unintelligible. The issue does, in a covert way, still trouble us. Wallace Matson (1967) ended

a philosophic defense of atheism with the words, “Still, why is there something rather than nothing?”. The doctrine that “you take the universe you get” (a remark Steven Weinberg once made in a discussion) sounds close to saying it’s some sort of metaphysical chance (we might just as well have anything). The idea of a super-sensible Cause outside of the universe leads at once to the question that troubled me when I was seven. We don’t even have the comfort of thinking of the universe as a kind of ens necessarium: it only came into existence

a few billion years ago! This situation was summed up by Kant: Kant held that the whole enterprise of

trying to demonstrate the existence and nature of a supersensible world by speculation leads only to antinomies. (The universe must have a cause; but that cause would have to have a cause; but an infinite regress is no explanation and self-causation is impossible…) Today, as I remarked, only a few relics would challenge this conclusion, which put an end to rationalism as well as to the medieval synthesis of Greek philosophy with revealed religion.

This decline of medieval philosophy was a long process which overlapped the decline of medieval science (with its substantial forms). Here too Kant summed up the issue for our culture: the medievals (and the rationalists) thought the mind had an intellectual intuition (intellektuelle Anschauung), a sort of perception that would enable it to perceive essences, substantial forms, or whatever. But there is no such faculty. “Nothing is in the mind that was not first in the senses except the mind itself, as Kant put it, quoting Leibnitz.

Again, no one but a few relics challenge this conclusion. But Kant drew a bold corollary, and this corollary is hotly disputed to the present day. The corollary depends upon a claim that Kant made. The claim can be illustrated by a famous observation of Wittgenstein’s. Referring to the “duck- rabbit” illusion (the figure that can be seen as either a duck or a rabbit), Wittgenstein remarked that while the physical image is capable of being seen either way, no “mental image” is capable of being seen either way: the “mental image” is always unambiguously a duck image or a rabbit image (Philosophical Investigations

II, xi, 194–6). It follows that “mental images” are really very different from physical images such as line drawings and photographs. We might express this difference by saying the interpretation is built in to the “mental image”; the mental image is a construction.

Kant made the same point with respect to memory. When I have a memory of an experience this is not, contrary to Hume, just an image which “resembles” the earlier experience. To be a memory the interpretation has to be “built in”: the interpretation that this is a past experience of mine. Kant (1933, “Transcendental Deduction”) argues that the notion of the past involves causality and that

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saying we “remember” them is saying we have succeeded in constructing a version with causal relations and a continuing self in which they are located.

The corollary Kant drew from all this is that even experiences are in part constructions of the mind: I know what experiences I have and have had partly because I know what objects I am seeing and touching and have seen and touched, and partly because I know what laws these objects obey. Kant may have been overambitious in thinking he could specify the a priori constraints on the construction process; but the idea that all experience involves mental construction, and the idea that the dependence of physical object concepts and experience concepts goes both ways, continue to be of great importance in contemporary philosophy (of many varieties).

Since sense data and physical objects are interdependent constructions, in Kant’s view, the idea that “all we know is sense data” is as silly as the idea that we can have knowledge of objects that goes beyond experience. Although Kant does not put it this way, I have suggested elsewhere (Putnam, 1981, ch. 3) that we can view him as rejecting the idea of truth as correspondence (to a mind- independent reality) and as saying that the only sort of truth we can have an idea of, or use for, is assertibility (by creatures with our rational natures) under optimal conditions (as determined by our sensible natures). Truth becomes a radically epistemic notion.

However, Kant remarks that the desire for speculative metaphysics, the desire for a theory of the furniture of the world, is deep in our nature. He thought we should abandon the enterprise of trying to have speculative knowledge of the “things in themselves” and sublimate the metaphysical impulse in the moral project of trying to make a more perfect world; but he was surely right about the strength of the metaphysical urge.

Contemporary materialism and scientism are a reflection of this urge in two ways. On the one hand, the materialism claims that physics is an approximation to a sketch of the one true theory, the true and complete description of the furniture of the world. (Since he often leaves out quantum mechanics, his picture differs remarkably little from Democritus’: it’s all atoms swerving in the void.) On the other hand, he meets the epistemological argument against metaphysics by claiming that we don’t need an intellectual intuition to do his sort of metaphysics: his metaphysics, he says, is as open ended, as infinitely revisable and fallible, as science itself. In fact, it is science itself! (interpreted as claiming absolute truth, or, rather, claiming convergence to absolute truth). The appeal of materialism lies precisely in this, in its claim to be natural metaphysics, metaphysics within the bounds of science. That a doctrine which promises to gratify both our ambition (to know the noumena) and our caution (not to be unscientific) should have great appeal is hardly something to be wondered at.

This wide appeal would be reason enough to justify a critique of metaphysical materialism. But a second reason is this: metaphysical materialism has replaced

238 HILARY PUTNAM intellectual tendencies, a critique of its most influential contemporary form is a

duty for a philosopher who views his enterprise as more than a purely technical discipline.