Things which I'd desperately like to get done before I die of old age:
1. Solving the problems of induction (Hume's, and Goodman's)
I favour an objective Baysian approach based on algorithmic probability (as per Solomonoff, although Solomonoff's ideas only get you so far). The approach involves using probabilistic universal Turing machines to define a prior probability distribution. The tricky bit is, of course, providing a rational justification for choosing one such prior rather than another. I'd like to think I've got a way of doing this. (I developed an early version of the idea in my MSc thesis, but subsequently realised that what I said in the thesis was wrong.)
One small piece of the puzzle is dealt with in my 2013 paper, The Semimeasure Property of Algorithmic Probability -- "Feature" or "Bug"?
2. Naturalising intentionality
I favour a theory that is internalist and functionalist (or, better, computationalist). That is, I think that the content of thought depends on what computations are going on inside the brain. (How do I deal with Twin Earth cases? By going two dimensional, in the usual way. Two dimensional semantics gives a nice account of how a kind of "narrow content", that supervenes on what is inside the head, can exist side by side with a "wide content" that depends on external, environmental factors.) The particular approach I favour rests on the idea that the brain represents the world by virtue of building a computational model or theory about the external world. (Roughly speaking, the brain is a "little scientist" or a little 'inductive reasoning machine" that is trying to make sense of its sensory input by formulating a hypothesis about the causal structure of the external world.) My account of how the narrow content of a representation is to be 'read off' the resulting state of the brain has more in common with the positivist's verificationist theory of meaning than with more modern teleosemantical or co-variational approaches, which I think are on completely the wrong track.
Again, I did a lot of work on this topic in my MSc thesis, and again I have subsequently come to recognise that what I said in that thesis was mostly wrong.
3. Octopropositionalism
This is my name for the idea that all eight of the following modal categories are occupied by propositions:
- NAA1: Necessary, A priori and Analytic
- NAS2: Necessary, A priori and Synthetic
- NEA3: Necessary, Empirical and Analytic
- NES4: Necessary, Empirical and Synthetic
- CAA5: Contingent, A priori and Analytic
- CAS6: Contingent, A priori and Synthetic
- CEA7: Contingent, Empirical and Analytic
- CES8: Contingent, Empirical and Synthetic
Needless to say, this is an unorthodox view! Hume held that only NAA1 and CES8 propositions exist (his 'relations of ideas' and 'matters of fact'). Descartes thought there are CAS6 propositions ('a thinking thing exists'). Kant added NAS2 propositions to the mix. Kripke gave us a priori contingencies (that are either CAA5 or CAS6, depending on whether they are analytic or synthetic), and empirical necessities (NEA3 or NES4). Kaplan gives us a CAA5 proposition, in the form of 'I am here now'. But to the best of my knowledge no one before has tried to show that all the modal categories house propositions. My paper arguing for Octopropositionalism is finished. I'm trying to find a home for it now.
4. Doxastic Desire and Attitudinal Monism
I endorse a particular 'desire as belief' theory--i.e., a theory which says that desires can be reductively analysed as being beliefs of a certain sort. (On a very rough first pass, to desire that p with a strength of x is to believe that p's being true would be 'valuable' to degree x.) I think my theory has major advantages over various such 'desire as belief' theories now on the market. If some such theory true then this has important implications both in the philosophy of mind (naturalising the propositional attitudes gets a lot easier if there is only one fundamental attitude) and in metaethics (where it supports a cognitive internalist solution to Michael Smith's 'moral problem').
As of late 2016 my paper on this is out in Synthese.
As of late 2017, a followup paper attacking a famous anti-Desire-As-Belief argument of David Lewis' is being published by the Polish Journal of Philosophy.
I endorse a particular 'desire as belief' theory--i.e., a theory which says that desires can be reductively analysed as being beliefs of a certain sort. (On a very rough first pass, to desire that p with a strength of x is to believe that p's being true would be 'valuable' to degree x.) I think my theory has major advantages over various such 'desire as belief' theories now on the market. If some such theory true then this has important implications both in the philosophy of mind (naturalising the propositional attitudes gets a lot easier if there is only one fundamental attitude) and in metaethics (where it supports a cognitive internalist solution to Michael Smith's 'moral problem').
As of late 2016 my paper on this is out in Synthese.
As of late 2017, a followup paper attacking a famous anti-Desire-As-Belief argument of David Lewis' is being published by the Polish Journal of Philosophy.
5. Physicalism and phenomenal consciousness
I'm a physicalist. I think mental states in general, including states of phenomenal consciousness, are identical to functionally characterised brain states. (So I am a physicalist of an identity theorist cum functionalist stripe). The main tasks for someone such as myself are to: (i) refute the various anti-materialist arguments; and (ii) articulate a positive theory which adequately explains the various weirdnesses of phenomenal consciousness.
My paper, "The inconceivable popularity of conceivability arguments" (published in Philosophical Quarterly in late 2016), co-authored with my colleague, Jack Copeland, and our PhD student, Zhao-Ran Deng, takes aim at conceivability arguments in general and two famous anti-materialist conceivability arguments in particular--namely, Kripke's modal argument and Chalmers' zombie argument.
As of late 2017, a followup article in which I hammer home the refutation of the zombie argument is under submission.
I have other arguments up my sleeve against Levine's 'explanatory gap' argument, and against both Nagel's bat argument and Jackson's knowledge argument (which I understand as being quite distinct arguments). And I have a theory of qualia waiting in the wings. This is all stuff I've had sitting in various half written papers on my computer's harddrive for years. Need to get them finished!
6. Descartes' cogito, the anthropic principle, and a second hard problem of consciousness
This is a big, sprawling, messy idea that I think is terribly important but that I have a hard time persuading other people to take seriously. Basically, I think that ether are at least two hard problems of consciousness, not just one. Yes, phenomenal consciousness poses a 'hard' problem; but so too does another kind of consciousness which I call 'a priori consciousness'. This is the kind of consciousness at issue in: (i) the Cartesian cogito argument; (ii) Rawls' 'veil of ignorance'; and (iii) the anthropic principle. My PhD thesis was all about this. I've made one unsuccessful attempt to turn it into a publication. Watch this space!
7. Tablism
This is my metaphysics. On first sight it appears manifestly false, and it is starkly counterintuitive, but I think it is true. The idea is that our actual world is, at bottom, just a row in a truth-table--a stupendously large truth table, which I call 'The Table', having a row for every possible world there is. It is a theory obtained by taking two cups of Kant, one cup of Lewis, a small sprinkle of the early Wittgenstein and stirring them together vigorously while reciting the magic words, 'I will be guided by logic and reason, not by intuition'. It solves a whole bunch of big metaphysical and cosmological problems.
I'm working on this as a matter of priority.
8. 'Squaring up' two dimensional semantics
I like the Jackson/Chalmers 'epistemic' version of 2D semantics. It seems to me that what it says about the Kripke/Putnam/Burge cases is exactly right. Well, almost exactly right. I think there is some room for improvement regarding a few of the technical details.
9. Reticent logic and the Penrose/Lucus/Godel argument against artificial intelligence
My paper, Why We Shouldn't Reason Classically, and the Implications for Artificial Intelligence, sets out the basic idea, but there is a lot more to say. That paper starts by describing something I call the "prisoner's scenario". I think the implication of the prisoner's scenario for how we understand logic are pretty far reaching. I've got a paper in the works in which I argue that the whole idea that logic is the science of validity is wrong.
10. De-extinction
On a completely different tack, one of my former PhD students, Mick Whittle, got me working on de-extinction. It's an exciting, very new area that throws up a lot of deep philosophical questions.
My review essay on Beth Shapiro's book, "How to Clone a Mammoth" (in Biology and Philosophy) lays out my basic position as regards (i) the ethics of species de-extinction and (ii) how the authenticity of de-extinct organisms is to be assessed.
A followup article in the Animal Studies Journal (titled 'On the Authenticity of De-extinct Organisms, and the Genesis Argument') explains why, in my view, de-extinct animals have the right phylogenetic history to be authentic members of the original, extinct species, their unnatural mode of creation notwithstanding.
My 2017 book, Resurrecting Extinct Species: Ethics and Authenticity, co-authored with Mick Whittle, provides an overview of the philosophy of de-extinction.