Some of my colleagues and I are trying to come up with a dialectical/historical map of panpsychism. In what follows let us label any view that (without substantial change in meaning) attributes to the world categories that we might most naturally attribute to human minds. Panpsychism needn't be pan-theism or panentheism (the view that the physical universe is part of God), though one might argue that pan-theism should entail pan-psychism. To the extent that Spinoza is fairly labelled a pantheist, one can actually tell the story of German Idealism in terms of this issue.
Anyhow, here are the three main strands I could think of:
- Post-Cartesian Panpsychism- This form comes out of the difficulty of making sense of how the mind and it's properties could exist if the non-mental world lacked those properties. The two people who have done the most to help the development of this kind of pan-psychism are David Chalmers and Galen Strawson. Note that this kind of panpsychism is not a priori committed to the claim that we can't make sense of the mind given the way physics describes the world. To the extent that doing physics might require attributing mental properties to a world we previously thought was non-mental physics (and on some interpretations of quantum physics this is the case), then physics might actually end up providing support to Post-Cartesian Panpsychism.
- Early Schelling*/Hegelian/post-Heideggerian/post-McDowellian Panpsychism- Hegel can profitably be read as holding that one must either be a skeptic or attribute the kind of teleological properties that post-Cartesian science was locating entirely in the human (and God's) minds to the universe as it is in itself. Much of his Phenomenology can be understood as a deconstruction of skepticism, so that (given the dichotomy) the teleological conception of reality can be assumed when working out a positive metaphysics. Martin Heidegger's revolt against neo-Kantianism has been the biggest impetus for a return of this kind of pantheism. For Heidegger, descriptive vocabulary (Sellars' "space of causes") is actually founded on normative vocabulary. There is some sense in which we can't help but seeing the world as always already a site of deontic modals that are already there. But then, as soon as you ask if the world really is that way, you are confronted with Hegel's dichotomy between skepticism and metaphysical teleology. Note that this is precisely why there are quietist strands in Heidegger and McDowell. They accept the epistemic primacy of the space of reasons, but by undermining questions about the way the world really is they hope to not accept the metaphysical primacy in the sense of the Hegelian strand of panpsychism.
- Late Schelling/Schopenhaurian/Nietzschean Panpsychism- If Hegelian pantheism concerns deontic modals, then Schopenhaurian panpsychism concerns alethic modals. Grossly simplified, the idea is like this. Contra Hume our inner phenomenology reveals what it is like to be frustrated and this gives us a qualitative experience of relative forms of impossibility and possibility. Then, once one agrees with Schelling that one is nature, one realizes that what happens in one's own body is happening in the world as it is, a metaphysics of will is born. Strangely, philosophers who find psychologically rich forms of alethic modality in the world as it is in itself have tended to be hostile to philosophers who find psychologically rich forms of deontic modality in the world. This might just be because of personal issues between Hegel and Schopenhauer. I don't know. I don't know the extent to which Bergosonian, Whitehead, and Deleuze should be understood as in this pantheistic tradition.
For me, the biggest contribution that Speculative Realism made to contemporary philosophy is to open up questions about the latter two forms of panpsychism, and to renew work in traditions where it's already been opened up (guerilla readings of classical phenomenologists, Simondon not just as a precursor to Deleuze, late period Merleau Ponty, new Spinozism, metaphysical readings of Deleuze, Derrida, etc. etc. etc.). I hope to do a post about this in a couple of days. But I'd be really interested if anyone has anything to add or detract from the above typology.
*This way of marking out two Schelling's is crude. On this, see especially J.A.F. Marshall's excellent review of S.J. McGrath's The Dark Ground of Spirit: Schelling and the Unconscious (hat-tip Peter Gratton).]