1. Following a link provided in an April 9th, 20103, post, “KCL’s David Papineau Interviewed…,” in Leiter Reports: A Philosophical Blog, I found myself reading Richard Marshall’s 3am Magazine interview of David Papineau. This was, I blush to admit, the very first time I had come across even Papineau’s name; thus the “First Impression” of the subtitle of this post.
The paragraph introducing the interview reads:
David Papineau is still roving in the deep philosophical waters even though he knows that he’ll never know everything. He keeps writing hard core books about his philosophical thoughts covering things such as physicalism and how come everyone isn’t a physicalist, substance and property dualism and Kripke’s worry that the mind brain identity is just contingent. He wonders why philosophers think there’s something wrong with just knowing the facts. He thinks about the nature of colour experiences, representation, and avoids mixing up methodological issues with metaphysical ones. He thinks about the significance of Schrodinger’s cat, about whether there are any special laws that are not reducible to physics and about the usefulness of ‘historical kinds.’ This is a deep water big beast from the philosophical depths: bangin’.
A “deep water big beast from the philosophical depths” and “bangin’” indeed! I, however, very much a land creature and wanting to approach the beast with caution and in doing so above all to keep my head above water, will restrict this post to some brief reflections on but one of the topics just raised, Papineau’s physicalism.
2. Marshall brings up Papineau’s physicalism by observing and then asking:
You are an ontological naturalist. You think that modern science makes some species of physicalism an irresistible position don’t you? Can you explain what your arguments are?
Instead of the requested plurality of arguments on behalf of his physicalism, Papineau offers but one assertion, of the thesis of the “causal completeness of physics,” in two equivalent formulations:
It’s simple enough. Nearly everybody nowadays accepts the ‘causal completeness of physics’—every physical event (or at least its probability) has a full physical cause. This leaves no room for non-physical things to make a causal difference to physical effects.
Papineau then goes on to offer an argument one unexpressed premise of which is the thesis of the “causal completeness of physics”:
But it would be absurd to deny that thoughts and feelings (and population movements and economic depressions . . .) cause physical effects. So they must be physical things.
I will indulge myself in the Aristotelianism of my neo-Aristotelianism by restating first the assertion and then the argument, in the classical forms which thinkers of my ilk find it most comfortable to deal with.
3. a. First, then, stripping away the irrelevancies, i.e., the remark about simplicity and the assuredly empirical in intention but not necessarily true statement about what everybody accepts, I take it that the thesis of the “causal completeness of physics” can be reduced to the universal affirmative proposition that:
All causes of physical effects are physical causes.
The “full physical cause” of Papineau’s statement of the thesis of the “causal completeness of physics” is captured, I think, with the proposition that:
Only physical causes are causes of physical effects.
This proposition, however, is logically equivalent to the universal affirmative proposition about all causes of physical effects given just above.
3. b. For its part, the assertion that the thesis of the causal completeness of physics “leaves no room for non-physical things to make a causal difference to physical effects” is suitably regimented as the proposition that:
No non-physical causes are causes of physical effects.
This proposition in turn is equivalent to its converse, the proposition that:
No causes of physical effects are non-physical causes.
And this last proposition is nothing but the obverse of the universal affirmative proposition presented above and thus, strictly speaking, equivalent to it.
4. Turning now to the argument, we have in hand one of its two premises, the major, the proposition that:
All causes of physical effects are physical causes.
The other, minor, premise can be arrived at in two steps. In the one, by stripping the editorial comment from, abbreviating, and regimenting the statement that “it would be absurd to deny that thoughts and feelings (and population movements and economic depressions . . .) cause physical effects,” we arrive at:
Thoughts (etc.) are causes of physical effects
The second step is that of supplying the missing quantifier. Here we have a choice to make, between assuming that the intended proposition is a universal proposition and assuming that it is a particular proposition. If we adopt the former assumption, we arrive at:
All thoughts (etc.) are causes of physical effects.
With this assumption, Papineau’s argument is, then, a categorical syllogism of the kind known in the logical tradition as Barbara:
All causes of physical effects are physical causes.
All thoughts (etc.) are causes of physical effects.
Therefore, all thoughts (etc.) are physical causes
If, on the other hand, we adopt the latter assumption, we arrive at:
At least some thoughts (etc.) are causes of physical effects.
With this assumption, Papineau’s argument becomes a categorical syllogism of the kind known in the logical tradition as Darii:
All causes of physical effects are physical causes.
At least some thoughts (etc.) are causes of physical effects.
Therefore, at least some thoughts (etc.) are physical causes.
5. Let’s assess that which the 3am interview has presented us of Papineau’s thought with respect to the thesis of the “causal completeness of physics.” First, we should note with Papineau that the argument having it as one of its premises does not in fact demonstrate that physicalism is true without qualification. As he puts it:
Note how this argument only bites for those things that do have physical effects. If numbers say, or moral properties, have no physical effects, then this argument gives us no immediate reason to say that they too must be physical.
It leaves it possible, that is, that there are non-physical beings which are not causes of physical effects. There could still be thoughts, if, while at least some thoughts are causes of physical effects, at least some thoughts are not causes of physical effects. There could even be a divine being, though not one having physical effects.
More significantly, we can observe that while it is absolutely evident that Papineau’s argument, whether it be one in Barbara or one in Darii, is utterly valid, it is not evident that it is sound. That is, neither of the two premises of his argument is self-evident; they both require proof. And nowhere, unless I am somehow mistaken, do we see in the 3am interview any argument on behalf of, let alone a proof of, either one.
I intend, therefore, to explore Papineau’s thought further, to discover what I can beyond this first impression. The question immediately arises, of course, of whether that intention will have any physical effect.
Postscript: Wishing to find out more about Papineau’s thought and his book, Philosophy, in particular, I went to the Oxford University Press site and read the following exposition of the book’s table of contents, presented herein as accurately as possible:
Table of Contents
Introduction
. World
2. Mind and Body
3. Knowledge
4. Faith
5. Ethics and Aesthetics
6. Soceity
Bibliography
Index
Text Acknowledgments
Picture Credits
After Aristotle 