I like the 'evidential' version of the argument suggested by Both Sides Brigade's comment. It just seems incredible (given our current scientific knowledge) to think that physical causes are insufficient to explain the functioning of our brains and bodies, or that non-physical stuff intervenes in the domain of physics. I can't take that seriously. So that's why I find interactionist dualism non-credible.
Is it "question begging"? I guess it depends whether some people may be initially drawn to interactionism without attending to these theoretical costs. They're pretty blatant, it's true, but people do sometimes overlook obvious things, so it still seems worth highlighting.
Compare the argument against cultural relativism from the objective wrongness of genocide. It's "question begging" in the same way -- it would seem so to a sophisticated defender of the view. But it still (rightly!) persuades many students who were initially drawn to relativism, because they just hadn't thought about this obvious problem with their view.
I think causal closure arguments are popular primarily because so many people have the general notion that we shouldn't carve out exceptions to an extremely well-confirmed theory with tremendous explanatory power merely because we encounter a specific case in which a poorly understood phenomenon fails, at first glance, to adhere to it. I'm sure dualists are sick of this comparison, but it's a lot like the debate over vitalism in the 19th century - in that case, "All matter is governed entirely by physical and chemical laws" was begging the question against vitalists, but the persuasive power of that premise nonetheless animated many of the most powerful arguments against vitalism and we all now look back and realize the vitalists were rash in dismissing it. I don't think these nominally question-begging arguments are really meant to be convincing on their own. They're more meant to foreground the high cost of the competing theory. Maybe it would be better to think of an Evidential Argument From Causal Closure that goes something like :
1) All well-understood phenomena adheres to causal closure.
2) Consciousness is a poorly understood phenomenon.
3) If all phenomena adheres to a particular principle, with the exception of a single poorly understood phenomenon that appears not to, then it is more likely that we are misunderstanding the single poorly understood phenomenon than that the particular principle is false.
4) It is more likely that we are misunderstanding consciousness than that causal closure is false.
5) We are justified in believing that causal closure is true.
6) We are justified in believing interactionist dualism is false.
Of course, a dualist can just insist that their introspective awareness of consciousness is such that they simply cannot be mistaken and they are therefore justified in dismissing the general principle no matter how solid it seems elsewhere - much like a Christian could insist that their introspective awareness of Jesus' love is such that they simply cannot be mistaken and they are therefore justified in dismissing the idea that no one comes back to life after being dead for three days. But I definitely find that baffling, both because the introspective awareness of consciousness I do have gives me many reasons to believe it is illusory in many important respects and because my other views about evolution and human psychology give me no reason to believe introspection would reveal the true nature of my consciousness anyway. But of course that's a broader debate!
This would be a terrible argument. Premise 1 is flagrantly question-begging"
Have you seen a disembodied mind? The evidence against disembodies minds is about the same as the evidence against unicorns.
"But the interactionist disputes this—they say we have observed a nonphysical cause. It’s called consciousness."
Except that the nonphysicality of consciousness isn't a directly observable empirical fact: the arguments for nonphysicality are very much about the success and failure of various kinds of explanation.
"So why is this argument convincing to many people?"
Strict physical determinism, if it were true, would be a strong argument for causal closure, since the alternative would be overdetermination, ie. the mental causing events that have already been sufficiently caused by physics.
You premise 1 immediately reminded me of the premise: "No amount of knowledge could have greater intrinsic goodness than some large finite amount of pain has intrinsic badness." What non-hedonist is going to accept that?
I like the 'evidential' version of the argument suggested by Both Sides Brigade's comment. It just seems incredible (given our current scientific knowledge) to think that physical causes are insufficient to explain the functioning of our brains and bodies, or that non-physical stuff intervenes in the domain of physics. I can't take that seriously. So that's why I find interactionist dualism non-credible.
Is it "question begging"? I guess it depends whether some people may be initially drawn to interactionism without attending to these theoretical costs. They're pretty blatant, it's true, but people do sometimes overlook obvious things, so it still seems worth highlighting.
Compare the argument against cultural relativism from the objective wrongness of genocide. It's "question begging" in the same way -- it would seem so to a sophisticated defender of the view. But it still (rightly!) persuades many students who were initially drawn to relativism, because they just hadn't thought about this obvious problem with their view.
I think causal closure arguments are popular primarily because so many people have the general notion that we shouldn't carve out exceptions to an extremely well-confirmed theory with tremendous explanatory power merely because we encounter a specific case in which a poorly understood phenomenon fails, at first glance, to adhere to it. I'm sure dualists are sick of this comparison, but it's a lot like the debate over vitalism in the 19th century - in that case, "All matter is governed entirely by physical and chemical laws" was begging the question against vitalists, but the persuasive power of that premise nonetheless animated many of the most powerful arguments against vitalism and we all now look back and realize the vitalists were rash in dismissing it. I don't think these nominally question-begging arguments are really meant to be convincing on their own. They're more meant to foreground the high cost of the competing theory. Maybe it would be better to think of an Evidential Argument From Causal Closure that goes something like :
1) All well-understood phenomena adheres to causal closure.
2) Consciousness is a poorly understood phenomenon.
3) If all phenomena adheres to a particular principle, with the exception of a single poorly understood phenomenon that appears not to, then it is more likely that we are misunderstanding the single poorly understood phenomenon than that the particular principle is false.
4) It is more likely that we are misunderstanding consciousness than that causal closure is false.
5) We are justified in believing that causal closure is true.
6) We are justified in believing interactionist dualism is false.
Of course, a dualist can just insist that their introspective awareness of consciousness is such that they simply cannot be mistaken and they are therefore justified in dismissing the general principle no matter how solid it seems elsewhere - much like a Christian could insist that their introspective awareness of Jesus' love is such that they simply cannot be mistaken and they are therefore justified in dismissing the idea that no one comes back to life after being dead for three days. But I definitely find that baffling, both because the introspective awareness of consciousness I do have gives me many reasons to believe it is illusory in many important respects and because my other views about evolution and human psychology give me no reason to believe introspection would reveal the true nature of my consciousness anyway. But of course that's a broader debate!
"There are no disembodied minds.
If God existed, he’d be a disembodied mind.
Therefore, God doesn’t exist.
This would be a terrible argument. Premise 1 is flagrantly question-begging"
Have you seen a disembodied mind? The evidence against disembodies minds is about the same as the evidence against unicorns.
"But the interactionist disputes this—they say we have observed a nonphysical cause. It’s called consciousness."
Except that the nonphysicality of consciousness isn't a directly observable empirical fact: the arguments for nonphysicality are very much about the success and failure of various kinds of explanation.
"So why is this argument convincing to many people?"
Strict physical determinism, if it were true, would be a strong argument for causal closure, since the alternative would be overdetermination, ie. the mental causing events that have already been sufficiently caused by physics.
You premise 1 immediately reminded me of the premise: "No amount of knowledge could have greater intrinsic goodness than some large finite amount of pain has intrinsic badness." What non-hedonist is going to accept that?