Ilion, a regular poster at Uncommon Descent, linked to an argument for God that he makes on his blog, here. I found it interesting because it was exactly the argument (though more succinctly expressed, I think) that kept me a theist for most of my life):
The reality of minds in a material world (thus, every human being who has ever existed) is proof that atheism is false. If atheism were indeed the truth about the nature of reality, then we would not — because we could not — exist. But we do exist. Therefore, atheism is not the truth about the nature of reality.
My position was that as every one of us (I assume) has the experience I have of being aware – being a mind – and thereby of being a unique self – there must be something unique to me, that inhabits me, that is not simply a material body, which, I assumed, could carry on perfectly well, zombie-fashion, were that essential self to go on vacation for a bit. Which made an after-life perfectly reasonable: (I knew my body would cease to function, but as my self seemed to be unarguably independent of the body it inhabited, there seemed no reason to assume that it would not continue to exist independently once that body ceased to function).In other words, the conceivability of Philosophical Zombies seemed to me to be a powerful argument: if a body can exist without a mind, then minds and bodies are somewhat independent, in which case it’s reasonable to postulate that a mind can exist without bodies. I wasn’t sure how much they could actually do of course, because it seemed that bodies have important information-gathering, decision-making, and executive functions, but I figured that the entity morally responsible for those the body’s actions (which would otherwise be merely mechanical outputs from a morally neutral, if complex, machine) must be this self thing, and must have some sort of control – at least emergency control – of the levers. And, if morally answerable beyond the grave, answerable to some comparable mega–self thing, the self of the entire universe, perhaps, the self whose body was the entire universe but whose mind pre-existed it (if you can use the suffix “pre-” in the absence of time), even transcended it, but kept it in being and was responsible, ultimately, for its actions, in an analogous fashion to me and my body. So there was my starter-pack God, which seemed to work pretty well in most theologies.
As I say, Ilion puts it more starkly, but in so doing so, I think, he exposes the flaw more clearly than I did to myself.
He goes on to say:
GIVEN the reality of the natural/physical/material world, IF atheism were indeed the truth about the nature of reality, THEN everything which exists and/or transpires must be wholely reducible, without remainder, to purely physical/material states and causes.
and adds, in an edit:
But, since there exist entities and events in the world which are not wholly reducible, without remainder, to purely physical/material states and causes, then it is seen that the denial that ‘God is’ is a false proposition.
So the proof that “God exists” depends on the existence of “entities and events in the world that are not wholly reducible, without remainder etc”.
And his paradigm case of such an entity is: “our minds and all the functions and capabilities of our minds — including reason”.
Ilion’s argument takes the form of a reductio ad absurdum:
Now, specifically with respect to reasoning, what inescapably follows from atheism is that it is impossible for anything existing in reality (that included us) to reason.
When an entity reasons, it chooses to move from one thought or concept to another based on (its understanding of) the content of the concepts and of the logical relationship between them.
But, IF atheism were indeed the truth about the nature of reality, THEN this movement from (what we call) thought to though (which activity or change-of-mental-state we call ‘reasoning’) *has* to be caused by, and must be wholely explicable in terms of, state-changes of matter. That is, it is not the content of, and logical relationship between, two thoughts which prompts a reasoning entity to move from the one thought to the other, but rather it is some change-of-state of some matter which determines that an entity “thinks” any particular “thought” when it does.
Now, I’m no philosopher, as will be obvious, so let me try to parse this in a way that makes it clearer, at least to me:
- Reasoning involves mental state-to-mental state transitions.
- Under atheism (or the position that everything is “wholely reducible, without remainder, to purely physical/material states and causes”), these mental state-to-mental state transitions must be triggered by the “change-of-state of some matter”, not the content of the thought itself.
- This is absurd because we would then have to say that reasoning has nothing to do with the content of the reasoning.
- Therefore atheism (or the position that everything is “wholely reducible, without remainder, to purely physical/material states and causes”) is false
Let’s stipulate that by “reducible to” we mean the postulation that if we start with a brain in physical State A, in which it is about to present itself with a problem, it will get to State B, in which it has just completed solving the problem, we can (assuming a deterministic universe, for ease of imagining, and no external inputs between State A and State B) reproduce that process simply by starting again with a brain in State A . In other words, we can “reduce” the reasoning process to a reproducible cascade of brain states in which each state automatically follows the previous one, until the final state (“State B”) spits out the answer.
So in what sense would “content” be missing from such a process? Let’s say we made a robot that could do this, in just the way we propose that brains do it – we set the starting state of the robotic brain in such a manner that it is just about to formulate our problem, and switch it on, so that after a few milliseconds it reaches State A, and outputs the words: “hmm, if I had five apples and I gave away 2 what would happen?” and then we wait until that state cascades through another series of states until the robot reaches State B and outputs the words: “I’d have three left”.
Now, clearly, State A and State B have <i>content</i> in a straightforward sense – we set the robot so that it will articulate a problem “with content” for us and we will later receive answers “with content”. So I have to assume that Ilion means that the cascade of states that the brain in question (whether robotic, or the brain as conceived by an “atheist”) undergoes cannot have “content” from the point of view of the entity-with-the-brain. If so, Ilion has, in effect, reposed the zombie argument as:
- If we subtract from a person all the things that a zombie/robot could do (e.g. a reasoning task), we are still left with something for which the results of reasoning have content i.e. a remainder. Therefore atheism (or at least reductionism) is false.
And presumable that remainder is the thing I call “I” or “me”. But is it really a remainder? To assume that, is to assume that the mechanics that enable an entity-with-a-brain to spit out the answer to a reasoning problem are inadequate to account for any experience a thing-with-the-brain has of posing the problem to itself and figuring out the solution, and we know that people, namely things-with-brains, to have this experience. In other words, it is to assume that those mechanics cannot explain why there is an “I” who can appreciate the content of a person’s reasoning, even when nobody else is there. To assume, in fact, that producing a self-conscious robot is impossible.
Which seems to me to be assuming the consequent, and is thus fallacious.
This is always a problem with reductio ad absurdum arguments, of course, which are, essentially, arguments from incredulity. It’s easy to miss a bit, and think you’ve exposed an absurdity, when all you’ve exposed is your own unchallenged premise, and rendered your syllogism circular.
But is Ilion’s conclusion nonetheless correct? Is there a “remainder” when you subtract from a person all the mechanics that result in the cascade of mental states that follow the presentation of a reasoning problem to the states in which she spits out the answer (at least to anyone who cares to listen)? Or can we postulate a cascade of physical states in which a thing-with-a-brain can pose a question to itself, work through a reasoning process and appreciate the answer?
Well, yes, I think we can. But maybe we can figure that out, below 🙂