I’ve never understood the appeal to direct realism as a way of meeting the sceptical challenges. Let’s stipulate that direct realism can explain how I know that there’s a desk in front of me. There’s still a lot of my knowledge left unexplained. For instance, I know the Devil Rays didn’t win the World Series any year in the last 100, and they won’t win it this year. (I know this is a little like saying I know they’ll lose the lottery, but I don’t care. I’ve got a better chance of winning Powerball than the Rays have of winning the series, and I ain’t got a ticket. It’s a little odd saying the Rays didn’t win the years before they existed, but I think it’s still true.)
Maybe through a direct realist theory of testimony I can be directly acquainted with the Rays having not won the Series in the last century. I’m sceptical, but maybe. But there’s no plausible direct realist theory where I can be directly acquained with the Rays losing *this* year, when they haven’t yet been mathematically eliminated. It’s just induction. But induction can surely give me knowledge of things like this.
If you think I’m going out on a limb here with the prediction that the Rays won’t win the Series, I’ll back down a bit and say they won’t win the National League pennant. Right now they’re in the American League, but I think it’s logically possible that their affiliation gets changed mid-season, they go on a 25 game win streak as a result, and they wind up NL champs. Ain’t gonna happen though. How do I know? Not by direct acquaintance with this not happening, nor even by acquaintance with any _natural laws_ that prevent it. It’s a nomic possibility that the lords of baseball could come up with a plan as stupid as moving the Rays between leagues midseason. And, though this is a stretch, it’s a nomic possibility the Rays could win 25 straight. Still, it ain’t gonna happen. How do I know? Induction.
Now here’s why I’ve always been puzzled about the direct realist response to scepticism. If all we know is what we can directly perceive, then we have a very impoverished range of knowledge. We fail to know things that are Moorean facts. (I think it’s a Moorean fact that the Rays won’t win the NL pennant this year. I’m more confident of that than I am of Moore’s having had hands.) So even if direct acquaintance given us knowledge of some things, we still need induction to give us all the knowledge we take ourselves to have. But once we allow that knowledge can be extended by induction, then direct realism can do little epistemological work. For the inductive argument from sense data to the existence of an external world is very strong.
Now this isn’t to say that there are any reasons to believe in sense data, or that there are no other reasons to be direct realists. All I’m saying is the very weak point that we get little epistemological help from direct realism. That’s not bad news for direct realism, because we get little epistemological help from all manner of true theories. Perdurantism doesn’t help us respond to the sceptic either, and it’s still true. But unless we think knowledge of our immediate surrounds is knowledge enough, or the inductive argument from facts about our surrounds to facts about the wider world is good while the inductive argument from sense data to facts about the wide world is not, direct realism doesn’t help deal with scepticism. And that’s especially true if you think knowing how the baseball season will or won’t end is a more pressing epistemological matter than knowing whether one has hands. As, it turns out, I do.
Well, that was a bit of a rant, but I thought it was worth saying. I also thought most of the premises in my rant were fairly uncontroversial. But maybe not. If I recall correctly at the INPC Ram Neta reported to me that someone had said that on one reading Aristotle seems to endorse a direct realist solution to the problem of induction. And in the latest “No{u^}s”:http://www.blackwell-synergy.com/links/toc/nous/38/2 we see Marc Lange in his paper “Would “Direct Realism” Resolve the Classical Problem of Induction” doing something similar. Or at least that’s what he appears to be doing at first glance. Another paper to add to the ‘to be read carefully pile’. Maybe I’ll have to change my views on the relationship between perception and knowledge. (Of course it would be way cool if I could really _see_ that the Rays won’t win this year. It would be cooler still if I could see that the Yankees won’t win, but I think we need more than philosophy for that.)