I Love Deutsch's Ideas. I Still Think We're Pinballs.
I want to say something up front: I'm not here to dunk on David Deutsch. I've read The Beginning of Infinity (thanks for the copy, Cody). The stuff on good explanations, on knowledge as the thing that makes people and ideas hard to kill, on optimism as a discipline, genuinely great. I'm a fan.
But I think the free will part is where the whole framework gets used to protect a conclusion Deutsch wanted to be true, rather than one his own method would actually deliver as true. And I think a lot of people in his orbit have accepted it a little too easily, because it's flattering and because he's right about almost everything else.
So let's poke at it.
The chain nobody has broken
Here's my argument (well, it's a well known one held by smarter people than me but it's the one that I cannot shake as of yet). It's not subtle and I don't think it needs to be:
Quantum level: particles do what the rules make them do. No choosing. Classical physics: same, laws all the way down. Chemistry is physics with extra steps; molecules react the way their structure and energy states force them to. DNA, RNA, cells: chemistry in aggregate, doing what chemistry does. Brains: organisms' most elaborate trick, but built from the same atoms, running on the same rules, no exemption clause anywhere in the stack (in other words, clean computer code).
So when a brain "decides," what physically happened? A configuration of neurons, shaped entirely by genetics and every experience that configuration was ever exposed to, ran an electrochemical cascade that did, at every single step, what physics and chemistry compelled it to do. It felt like a choice. Feeling like a choice and being one are not the same claim, and nobody in the Deutsch camp has ever shown me the actual physical mechanism where a real fork opens up: a point where the next state isn't simply what the prior state made inevitable. They gesture at a different level of description instead. That's not the same thing as finding the fork.
And yes, this cuts both ways, and I mean for it to. Neither of us "chose" our position on this. David Deutsch didn't select free will as his view any more freely than the copper atom selected its spot on the statue. He's a pinball who writes very good books.
The statue trick, and why I think it's a dodge
The best comeback I know is the statue: why is there a particular atom of copper at the tip of a bronze statue's nose? You could trace it to the Big Bang (true, but useless). Or you could say: there was a war, a leader, a grateful public, a sculptor, a foundry. That's a good explanation in Deutsch's own technical sense, hard to vary, and it's where the real explanatory content lives. Free will, the argument goes, works the same way. Redescribing a decision in terms of neurons is worse, not more true.
I think this is a sleight of hand, and I want to say exactly where. "Good explanation" was built as a standard for which description is useful and informative. Somewhere along the way it got quietly promoted into a standard for what's metaphysically real, and nobody defending free will this way seems to notice the promotion happened. Those are two different jobs. A weather forecaster's model is the "good explanation" for whether it'll rain tomorrow (nobody's going to model every air molecule), and that in no way implies the atmosphere has genuinely open, uncaused branch points where it "chooses" to rain. Usefulness of a description is not evidence that the underlying process wasn't fully determined. If you think it is evidence, that's the actual claim you have to defend, and I haven't seen it defended. I've seen it assumed.
So here's the direct question, and I'd like an actual answer rather than the statue again: was the sculptor's decision caused, given the exact prior state of his brain and body and history, or wasn't it? If yes, you've just conceded the pinball. If no, you need to point to the physical mechanism that isn't caused, not a better vocabulary for describing a fully caused process.
The two things I won't pretend
I'll grant two things, because a Socratic argument that never concedes anything isn't Socratic, it's a monologue with question marks.
Quantum mechanics has real randomness in it, not merely complexity we haven't modeled yet. Fine. But randomness doesn't buy you free will: a decision caused by a coin flip in your skull isn't freer than one caused by a falling domino, it's just less predictable. Anyone reaching for quantum indeterminacy to rescue free will is smuggling in the same confusion I just accused the statue argument of: mistaking "not determined" for "chosen by me." Those aren't the same thing, and I don't think either side gets to have it both ways.
And no, I'm not saying the system of making choices is fake or that you should stop planning your life. Whatever this system is, it clearly weighs options, regrets, plans ahead. That machinery is doing real work. "It does real work" doesn't settle whether it was free, though, and I think that's exactly where a lot of people quietly stop asking questions because the alternative feels bad.
Where I actually land
I still think the pinball is the best explanation we have, not despite Deutsch's own standard, but by it. It's the account that's hardest to vary while covering every piece of evidence, from quarks to Churchill's nose to the sentence I'm typing right now. The "reasons and creativity" story is real and useful at its own level of description. But usefulness isn't an exemption from causation, and I think Deutsch has let a good rule of thumb about explanations quietly turn into a metaphysical escape hatch, because the alternative (that even his book was just where the pinball landed as it set of multitudes more) is uncomfortable to sit with.
If you think I've mangled the argument, don't hand me the statue again. Show me the actual fork in the physical chain: the place where the next state of a brain isn't simply what the prior state made inevitable. I'll go looking with you. But I'm not holding my breath.
