Grounds for a Sliver of Skepticism
Yesterday, Philosophy Bites released a brief podcast interview of me on skepticism. Listening to the interview now, I feel that I didn't frame my project as well as I might have, so I'll add a few remarks here.
I want to think about what grounds we might have for a non-trivial sliver of radically skeptical doubt.
There is, in my mind, an important difference between, for example, "brain-in-a-vat" skepticism and dream skepticism. Brain-in-a-vat skepticism asks you how you know that genius alien neuroscientists didn't remove your brain last night while you were sleeping, drop it into a vat, and start feeding it stimuli as though you were having a normal day. Dream skepticism asks how you know that you are not currently dreaming. The difference is this: There are no grounds for thinking that there's any but an extremely remote chance that you have been envatted, while there are some reasonable grounds for thinking there's a non-trivial sliver of a chance that you are presently dreaming.
It's crucial here to recognize the role played by theories that are probably wrong. It is, I think, probably wrong that people often have sensory experiences just like waking experiences when they sleep. Dreams are, in my view, always sketchy or even imagistic, rather than quasi-sensory with rich realistic detail. However, I'm hardly certain of this theory, and some prominent dream theorists argue that dream experiences are often highly realistic or even phenomenologically indistinguishable from waking life (e.g. Revonsuo 1995; Hobson, Pace-Schott & Stickgold 2000; Windt 2010). Contingently upon accepting that latter view, it seems to me that I ought to reasonably have some doubt about my current state. Maybe this now is one of those highly realistic dreams.
The idea here is that there are grounds for accepting, as a live possibility, a theoretical view from which it seems to follow that I might be radically wrong about my current situation. I don't prefer that theoretical view; but neither can I reject it with high certainty. It is thus reasonable for me to reserve a non-trivial sliver of doubt about my current wakefulness.
I would argue similarly with respect to two other skeptical possibilities: the idea that we are Artificial Intelligences living in a simulated world, and a somewhat less familiar form of skepticism I call "cosmological skepticism". In both cases, there are grounds, I think, for treating as a live possibility theories that, while probably not correct, would, if correct, imply that you might easily be radically wrong in many of your ordinary beliefs.
In concluding the interview, I also make an empirical conjecture: that seriously entertaining radically skeptical possibilities has the psychological effect of reducing dogmatic self-confidence and increasing tolerance, even regarding non-skeptical possibilities. I hope to more fully explore this in a future post.
Full interview here.
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