Actuality and Two Varieties of Possibility
In my previous post I contemplated the idea that actuality is the ontological delimiter of possibility (ODOP). That's a mouthful, but what it means basically is that the reason why one thing is possible rather than another is because something that already exists precludes some things from happening and not others. Here's a simple example: given the actual laws of nature, it is possible that a rock that is dropped will fall but (virtually) impossible that it will remain suspended in mid-air.
Matters are complicated, however, by the fact that there are different types of possibility. The example I just gave has to do with physical possibility. What is physically possible at a given time is delimited by the laws of nature and the physical state of the world at that time.
Another important type of possibility is logical possibility. Generally, something is logically possible if and only if there is a maximal, internally consistent state of affairs (a possible world) in which it exists. For example, is seems that there is a possible world that is just like our world except for the fact that the way colors appear is inverted--what appears red to us in this world appears blue to people in the other world, and vice-versa. Logical possibility is delimited by the laws of logic--most importantly, the law of non-contradiction--because that is what determines whether a maximal state of affairs is internally consistent or not.
There may be other types of possibility as well, but we can set them aside for now. It is important to note, however, that physical possibility is also constrained by logical possibility because physical possibilities are realized within the scope of a given possible world. It's natural, then, to focus first on logical possibility.
The issue now is this: If actuality is the ODOP, including logical possibility, then there must be some sort of reality that transcends all possible worlds. In other words, if W and V are different possible worlds then the actuality that delimits them both cannot be something that is merely actual in W or actual in V. Instead, it must be actual in both of them. And if there are other possible worlds, then it must be actual in them as well. In short, it must have universal transworld actuality. That, by the way, is what it means to be a logically necessary being.
So it seems that the thesis that actuality is the ODOP not only rules out the possibility of a null world (as I argued in the last post) but also requires sort of logically necessary being (or beings?). Moreover, since it is the laws of logic that delimit logical possibility, the laws of logic must either (a) be identical with this necessary being, (b) be part of this necessary being, or (c) be a production of this necessary being.
The examination of these options will have to wait for another post. One would I think be right to suspect at this point that the view that actuality is the ODOP looks rather favorable to theism. Conversely, Lewis's deflationary view of actuality is more amenable to atheism--as he points out in a follow-up to his "Actuality and Anselm" essay, his view of actuality gives him a fairly straightforward way of deflecting teleological (design) arguments for God's existence.
If this is right, then debates on the nature of existence and actuality are not neutral vis-a-vis theism and atheism. That recognition should, I think, give this issue greater importance than it generally receives in philosophical discussion.
posted by Alan Rhoda @ 9:30 PM
5 comments
links to this post
5 Comments:
Alan: Christopher was not a Fregean realist as you characterise him. He would not have said that predicates name Extramental Concepts or anything like that. His theory is quite simple. The sentence 'buttercups are blue' is equivalent to the sentence 'there are no blue buttercups'. All we are doing is shifting the adjective from one side of the copula to the noun side, thus 'blue buttercups', then sticking 'there' in front of 'are'. Just like the shift from 'a hobbit lived in a hole' to 'there lived a hobbit in a hole'.
You still haven't given any arguments to support your claim that there are two sense of 'is'. The argument that the class of blue buttercups is non-empty depends on the truth of 'some buttercups are blue', which you haven't established.
As for 'blue buttercups are possible', you need to show that this is not a variant of 'it is possible that there are blue buttercups'. If it is not, then your argument is just another version of the quantifier shift fallacy, i.e. the fallacious move from
Possibly for some x, buttercup(x) and blue(x)
which is true, to
for some x, for some x, buttercup(x) and blue(x)
which is not valid. It may be that the conclusion is true. But you have yet to supply a convincing argument for this.
As I have pointed out to Maverick, there is in my view a serious flaw in William's account of proper names. It is much more difficult to explain 'there is no such person as Mr Pickwick' on this Fregean account. But your arguments fail to exploit this weakness.
Hi Ocham,
I appreciate your clarifications on the differences between Frege and Williams. I understand you to be saying that Williams is just talking about language, whereas Frege thinks that there abstract concepts, propositions, and such independently of language. Is that right?
I did give an argument for distinguishing two senses of "exists" in my previous blog entry. Basically, my argument was that in order to make sense of talk about non-actual possibles (like the WTC) we need to distinguish a "there is" sense of "exists" from an "actuality" sense of "exists" (call these "exists1" and "exists2", respectively). Otherwise, we wind up in contradiction. Now that argument may be unsound (though I'm not clear as to why), but it is an argument.
At any rate, I'll get back to you on the buttercups over the next day or so. I've got to mull some of these matters over. Appreciate your input.
>>
I understand you to be saying that Williams is just talking about language, whereas Frege thinks that there abstract concepts, propositions, and such independently of language. Is that right?
<<
Not quite. Williams isn't *just* talking about language. Obviously there are non-linguistic items like trees, stones, cars, planets &c. The disagreement is whether predicates name entities, which Frege calls "concepts". I don't know whether Williams accepted 'propositions'. He was influenced by a logician called A.N. Prior, and Prior's view of propositions is not clear.
>>
I did give an argument for distinguishing two senses of "exists" in my previous blog entry. Basically, my argument was that in order to make sense of talk about non-actual possibles (like the WTC) we need to distinguish a "there is" sense of "exists" from an "actuality" sense of "exists" (call these "exists1" and "exists2", respectively). Otherwise, we wind up in contradiction. Now that argument may be unsound (though I'm not clear as to why), but it is an argument.
<<
My counter argument was that 'there is no bridge across the river at Hammersmith' appears to be the 'actual' sense. But in any case I don’t really follow your argument. The argument appears to be
(A) We cannot make sense of talk about non-actual possibles unless distinguish a "there is" sense of "exists" from an "actuality" sense of "exists".
but it begs the question. The expression 'talk about non-actual possibles' presumes there are such things as non-actual possibles. But this involves the quantifier shift fallacy I mentioned before. You are moving from
(B) It is possible that there are such things unicorns
which is true, but which is not a statement which implies there are such 'possibles', to
(C) Some things (unicorns) are such that they are possible
which does imply the existence of such possibles. But you have shifted the scope of the quantifier from inside the scope of 'it is possible that', to outside.
>>One would I think be right to suspect at this point that the view that actuality is the ODOP looks rather favorable to theism.<<
I'm a little uncomfortable with the move to theism. Granting your argument, we're left with quite a bare notion of God. Perhaps, as you suggest, the "logically necessary being[s]" are merely the laws of logic themselves. We could, at this point, appeal to conceivability a la Anselm, but I've never found that kind of argument persuasive. Do you see a more straightfoward path to theism following your modal argument?
Hi David,
Well, I've said that "the view that actuality is the ODOP looks rather favorable to theism," I'm not at all claiming to have established theism. There's still a fair distance to go to get from the existence of some sort of necessary being(s) to theism. Is there a quick route to theism from the "actuality is ODOP" starting-point? Maybe, but I'm not sure what it is. I'm going to try to carry the argument a bit further over the next few days, but I've also got a conference paper to finish writing this weekend. Right now that takes priority.
Post a Comment
Links to this post:
Create a Link
<< Home