Building up an argument against the existence of P-zombies
The argument goes as follows:
(1) If P-zombies exist, then there is a thing that is human and non-conscious.
(2) It is not the case that there is a thing that is human and non-conscious.
Therefore, (3) It is not the case that P-zombies exist.
It's a simple modus tollens.
(1) If P-zombies exist, then there is a thing that is human and non-conscious.
(2) It is not the case that there is a thing that is human and non-conscious.
Therefore, (3) It is not the case that P-zombies exist.
It's a simple modus tollens.
Comments (39)
Apart from the ones that happen to be asleep.
And what's the evidence for this?
It's like infinite regress of evidence.
Not necessarily. Presumably there's some sort of falsifiable evidence that hasn't yet been falsified which acts as a fundamental premise?
So, what's your objection to my argument?
That the second premise isn't supported.
What makes you think so?
I would take issue with this one. A physically identical being lacking consciousness is not human. It's a p-zombie.
But then we're arguing semantics and not whether p-zombies are possible.
Leaving aside all the problems tom alluded to with premise two, like sleeping persons and persons in comas:
We need to establish what exactly you mean by "human". I will assume you are referring to persons (in this case, human beings with thoughts of their own), not just the biological bodies of a human based on premise two. I can reject premise one, as under that definition, p-zombies are not human. They are simply animated human bodies that perfectly replicate the physical aspects of a person, right down to their brain waves, but do not possess consciousness.
If you want to argue human in terms of biological body, then premise two is false, as p-zombies would be human and not possess consciousness.
Also, to point out, p-zombies do not need to actually exist; they only need to be logically conceivable.
Many things are logically conceivable. Merely logically conceivable things can't refute anything. P-zombies are logically conceivable. Do P-zombies refute physicalism? I don't think so.
Then you do not understand the original p-zombie argument.
Logically conceivability entails logical possibility. Logical possibility means that there exists a possible world in which p-zombies exist. Therefore, there exists a possible world in which everything is physically the same, except that some of the "humans" are p-zombies i.e. physically identical, but not conscious. Therefore, what we call consciousness cannot be reduced to the physical, and therefore, there exists something beyond the physical, meaning physicalism is false.
Let's put an example to it:
There is our world. Let's call it World 1, or W1 for short. In this world, Chany is a person who has a physical body, brain waves and all that, and is conscious. There is another logically possible world, World 2, or W2 for short, that is exactly the same as W1 except that instead of Chany, there is p-zombie in place of Chany. Again, p-zombies are logically conceivable, meaning that they are logically possible; there is nothing wrong with W2 potentially existing. Let's call this p-zombie zombie-Chany. Chany and zombie-Chany are physically identical: same body, same brain states, everything. The only difference is that Chany has consciousness and zombie-Chany does not. Whatever explains this difference, it cannot be physical, as Chany and zombie-Chany are physically identical. Therefore, we need to appeal to something beyond physicalism to explain consciousness: therefore, physicallism is false.
So you're saying that the semantic content of statements in an argument matter? You were ignoring that idea with the p-zombie argument and only focusing on its form as a modus ponens.
The fact that you've just asserted it and haven't provided any evidence to support it.
This seems dubious to me unless we're simply saying that conceivability is logical possibility.
And with respect to logical possibility, what domain are we referring to for our background? That is, what set of statements forms our base, or are we referring to metaphysical/ontological facts, or what?
I ask because obviously if our background domain includes "physicalism is true" for example, then p-zombies aren't logically possible in that domain.
Is this by definition?
If a world exists it is an actual world, not a possible world (although of course insofar as a world is actual it must be also possible). Something being logically possible does not entail that it is anywhere actual.
The idea is that something is logically possible just when it isn't contradictory. Well, whether it's contradictory is relative to the domain we're considering. That could be metaphysical facts, or some set of statements, or whatever. If we're assessing whether "p-zombies are conceivable" is logically possible relatve to some set of statements, then it wouldn't be logically possible relative to a set of statements that includes "physicalism is true."
Sure, but "physicalism is true" is what's in question, so that would be assuming the conclusion.
Hence why I'm asking what we're saying it's logically possible with respect to.
If we're trying to determine whether physicalism is true, we can ask whether it's logically possible for there to be a duplicate physical world lacking some X from our world.
Of course, if you already know that physicalism is true, then you don't need to ask such questions. But then, how do you know that physicalism is the case?
Oy--this is just what I'm talking about though. Logically possible with respect to what? Metaphysical facts? Some set of statements? Logical possibility is relative to some domain. We're not simply asking whether "p-zombies are possible" isn't contradictory to itself, are we? That wouldn't tell us much.
We're asking whether physicalism logically entails all Xs. If it doesn't, then some Xs aren't physical.
What does it mean to "logically account" for something empirical? Sounds fancy, but I think it doesn't actually mean anything.
Physicalism isn't empirical. It's a metaphysical doctrine.
The bulk of metaphysics is ontology, no? And it's sounding more and more like you're simply giving up on trying to support the logical possibility/"logically account for" angle.
Ontology and empiricism are two different concerns.
Anyway, I meant to edit my post to add:
As such, it needs to show how everything is exclusively physical or made up of the physical.
Consider Thales: everything is water. So the challenge for water metaphysicians is to show how something like fire is made up of water.
You can substitute consciousness for fire, and physics for water. Colin McGinn titled his book on consciousness, "The Mysterious Flame", so it's apropos.
So ontology doesn't deal with empirical things in your view? Time isn't empirical for example? "Everything is water" isn't an empirical claim?
Empiricism is a matter of how we know, not what exists. So no, time isn't empirical, except in that we know about time by experiencing it. "Everything is water" is most certainly not an empirical claim, although empirical investigation can help or hurt such claims.
??? Check your dictionary maybe.
That everything we know is derived from sense-experience? That's still a matter of knowledge, not ontology. An empiricist might limit their ontology to what can be sensed, but that's still too different kinds of inquiry.
Also, one can be an empiricist and a skeptic about the nature of the external world. They fit quite well together.
I'm not talking about "empirical" in the sense of epistemological empiricism obviously.
What sense are you talking about it in? A peculiar one where you get to say that everything is physical, but don't have to back it up with ontological considerations?
In the sense where we're talking about the "furniture of the world" so to speak a la things that can be known via experience, whether directly or not, and whether extrapolatively/interpolatively or not.
So in all possible worlds where the furniture of the world is exactly the same, do you always have consciousness, intentionality, abstract categories, etc?
You're trying to skip to the "point" or "meat" of the argument. I'm not interested in that. I'm interested in what "logically possible" or "logically accounting for" is supposed to refer to, because I'm challenging that it refers to anything significant in the argument. I'm kicking at the supposed framework of the argument, I'm not looking to fall back into the main polemic of the two sides of the argument.
The rules of the game of life plus it's initial starting position logically entail any patterns that emerge during that game. If you had a super complex game of life such that there was something akin to characters and societies, with different levels of abstraction from which one could make sense of that game, they would all be logically entailed by the rules and starting conditions.
You could make a probabilistic game of life, and then the resulting complexity could be understood in terms of probabilities.
The question is whether physics is like that for all phenomena.
Well, then the answer to my question "logically possible with respect to what (domain)?" would be "the domain of metaphysical facts" then, no?