Modality and open future
February 25, 2009 — 9:06

Author: Alexander Pruss  Category: Free Will Open Theism  Comments: 29

I’ve been thinking what open future (OF) views can say about the modality of statements about the future. There are two OF semantics, which I’ll call N and F. Suppose Curley now exists, and that Curley’s freely taking the bribe is open. On the N semantics, Curley will freely take the bribe is neither true nor false. On the F semantics, it is false that Curley will freely take the bribe. The N semantics requires denial of excluded middle. The F semantics requires denial of the principle that, basically, not(will(p)) iff will(not(p)).

Suppose now that we say that a proposition p possibly/necessarily/impossibly is V iff p is V in some/all/no worlds, where V is a truth value or a logical combination of truth values like “neither true nor false”, which I will abbreviate “ntnf”. Let p be the proposition that Curley will freely take the bribe. On the F semantics, p is false in every world. For in some worlds Curley’s freely taking the bribe is open, and in those worlds p is false by that semantics. And in all other worlds, it is determined that Curley won’t freely take the bribe (e.g., because it is determined that there is no Curley, or that nobody will ever offer Curley a bribe, or whatever). So, in every world, p is false, and so p is necessarily false.

On the N semantics, things are more interesting. In worlds where Curley’s freely taking the bribe is open, p is ntnf. In worlds where Curley’s freely taking the bribe is not open, p is false. Therefore, on the N semantics, p is possibly ntnf and possibly false, and necessarily not true.

So what’s wrong with this? Well, one thing is that as Geoff Pynn pointed out in the previous discussion of open futurism, the open futurist surely wants to say that p is a “future contingent”. But if p is necessarily false, as it is on the F semantics, then that’s endangered. And if p is necessarily not true, then it’s also in a bit of trouble.


Counterintuitive Consequence of Open Theism
February 22, 2009 — 13:54

Author: Andrew Moon  Category: Open Theism  Comments: 17

I was talking w/Alan Rhoda at the Central APA, and I discussed with him the following counterintuitive implication of versions of open theism which say that all future contingents (or sentences about freely willed acts) are not true.
me: I bet that Curley will take the bribe tomorrow.
Alan: I don’t think he will.
me: let’s bet!
Alan: okay.
Tomorrow comes. Curley takes the bribe.
me: I was right!
Alan: I guess you were!
It seems that when I say “I was right!” I am ascribing truth to the sentence I uttered the day before. And intuitively, I speak truth when I ascribe truth to the sentence I uttered the day before. And if it is true that I correctly ascribe truth to the sentence I uttered the day before, then I did speak truth the day before. But some versions of open theism are committed to the counterintuitive implication that I did not speak truth the day before (i.e., utter a true sentence).
Two points: not all versions of open theism have to deal with this (e.g. Hasker’s). Secondly, I take this only to be some degree of negative evidence against open theism; perhaps there is more positive evidence for open theism.
I’ve heard this objection a lot in conversation, though I haven’t seen it in the literature. If I were an open theist, I’d just say that ordinary people have false views about the future, and so they are speaking incorrectly in these cases. Are there better ways out of this problem? Has there been any literature on this?

Open Theism and the Problem of Evil
December 10, 2008 — 8:35

Author: Alexander Pruss  Category: Molinism Open Theism  Comments: 20

It seems to me that some folks–perhaps not philosophers–think that Open Theism (OT) somehow significantly helps with the Problem of Evil. But I do not think it does. The natural reason to think OT helps is to say that if an omnipotent God foreknows that George will freely do some evil E, then God can prevent George from doing E, and OT means that God can’t foreknow it, so we can’t blame God for failing to prevent E. But this is confused. For it would be impossible for God to both foreknow–or even forebelieve–E and prevent E. Foreknowledge does let God put plans for an event into effect before the event happens, but for actual prevention of foreknown evils, what would be needed is Middle Knowledge, not foreknowledge.
I am curious if any philosophers have committed the error I criticize here.

The openness of the future and the past
December 9, 2008 — 9:26

Author: Alexander Pruss  Category: Open Theism  Comments: 6

Consider the following (non-deductive) line of reasoning in favor of an open future (cf. Rhoda, et al.):

  1. (a) Presentism is true, and hence (b) any facts that are true must be made true by present states of affairs. Moreover, (c) it is a cheat to allow such states of affairs as its being five minutes before George freely mows the lawn. (d) Without such cheats, the only way a fact about the future could be made true by a present state of affairs is if the present state of affairs causally necessitates the future fact. Since (e) not all future states of affairs are causally necessitated by present ones, (f) the future is open.

Now, consider the same line of reasoning with a past/present swap and a causal direction swap:

  1. (a) Presentism is true, and hence (b) any facts that are true must be made true by present states of affairs. Moreover, (c) it is a cheat to allow such states of affairs as its being five minutes after George freely mows the lawn. (d) Without such cheats, the only way a fact about the past could be made true by a present state of affairs is if the past fact is a necessary cause of the present state of affairs. Since (e) not all past states of affairs are necessary causes of present states of affairs, (f) the past is open.

Now I think 2a-d is precisely as compelling as 1a-d (in my view, neither is very compelling). There may be a difference, however, at step e in both cases. We have good reason to believe 1e, because of libertarian free will and quantum indeterminism. Do we have good reason to believe 2e? If we either believe in essentiality of origins or think that God is in time and his memories are caused by the state of affairs of which they are the memories, then we have some reason to deny 2e. Otherwise, it seems we would need to accept 2e–after all, apart from something like essentiality of origins and the issue of God’s memories, it seems like typically the effects produced by one cause, C1, could have been produced by another, C2. Thus, unless we believe in essentiality of origins or think that God is in time and has memories caused by the state of affairs of which they are the memories, if we accept 1a-f, we should likewise accept 2a-f. But 2f is absurd. Hence, we should likewise be very suspicious of argument 1 and its conclusion 1f.


Probability and Open Future Views
December 8, 2008 — 11:30

Author: Alexander Pruss  Category: Open Theism  Comments: 19

This is an attempt to make precise something I said in the comments to my previous post, and analyze it. Let T(p) be the claim that p is true. Work with epistemic probabilities. Assume the following three principles:

  1. p entails T(p)
  2. If p entails q, then P(p) is no greater than P(q)
  3. P(not-p)=1-P(p)

Let OF be the claim that the future is open, so that no proposition about a future contingent is true (i.e., it either lacks truth value, or it is false, depending on the version of OF). Let q be the claim that tomorrow I will toss a quarter a thousand times and each time it will land tails. Let p be not-q. Intuitively, P(p) is more than 1-2-1000 (more, because the chance that I will both to do the tossing is very small). Now OF entails not-T(p) (by definition of OF). Hence, P(OF) is no bigger than P(not-T(p)) = 1-P(T(p)) by (3). But P(p) is no bigger than P(T(p)) (by (1) and (2)) and hence 1-P(T(p)) is no bigger than 1-P(p). Thus, P(OF) is no bigger than 1-P(p). But P(p) is more than 1-2-1000. Hence, P(OF) is less than 2-1000. Hence, OF is not worthy of belief.

But in writing this argument out rigorously, it became clear that there is a way in which it begs the question against those defenders of OF who deny excluded middle. For (3) implies a probabilified version of the axiom of double negation (the axiom of double negation is: not-not-p entails p), and double negation has to be denied by those who deny excluded middle. So the defender of OF can get out of the argument if she denies the axiom of double negation, and gives a propositional probability theory compatible with that denial. But to deny double negation is to go pretty far down the road of implausibility–all reductio arguments go down the drain at that point. Of course one might maintain double negation for non-future-tensed claims, but that’s ad hoc.

A sound argument against Open Theism
December 5, 2008 — 14:04

Author: Alexander Pruss  Category: Open Theism  Comments: 29

The following argument is sound:

  1. Tomorrow I will freely eat dinner. (Premise: I have good albeit fallible inductive knowledge of this)
  2. God infallibly knows every true proposition that it is (metaphysically) possible to infallibly know. (Premise)
  3. If God infallibly knows p and God infallibly knows q, then God infallibly knows everything entailed by the conjunction of p and q. (Premise)
  4. Possibly, God infallibly knows that I will eat dinner tomorrow. (Premise)
  5. Possibly, God infallibly knows that tomorrow I will eat dinner freely or not eat dinner. (Premise)
  6. I will eat dinner tomorrow. (By (1))
  7. God infallibly knows (6). (By (2), (4) and (6))
  8. Tomorrow I will eat dinner freely or not eat dinner. (By (1))
  9. God infallibly knows (8). (By (2), (5) and (8))
  10. (6) and (8) entails (1). (Conceptual truth)
  11. God infallibly knows (1). (By (3), (7), (9) and (10))
  12. If Open Theism is true, God does not infallibly know anything I will freely do. (Premise)
  13. Open Theism is false. (By (11) and (12))


A methodological remark on open theism
December 5, 2008 — 12:25

Author: Alexander Pruss  Category: Concept of God Open Theism  Comments: 15

Suppose I have a new account of, say, omnipotence. Presumably, I still want to still claim that the attribute that I have given an account of is sufficiently close to the traditional understanding of the attribute that we are talking about the same attribute, and I am not simply denying that God has omnipotence in the traditional understanding, but clarifying. This is going to be a vague matter to some degree. But I do want to propose one necessary condition: My understanding of the attribute should be compatible with what my religious tradition takes to be central, paradigm cases of the exercise of that attribute.
An account of divine justice on which rewarding the just simply was not an option would depart too far from the traditional understanding, since rewarding the just is a paradigm case of the exercise of divine justice according to the tradition. Likewise, creation and miracles are paradigm cases of the exercise of omnipotence. An account of omnipotence on which one of these two was impossible would not be an account of omnipotence. This is true even if the account accepted traditional verbage like: “God can do anything that’s logically possible”, but added that creation or miracles are logically impossible.
On the other hand, if one departs somewhat from traditional wording, but keeps the paradigm cases, one has more of a hope of maintaining that one is merely clarifying. Thus, even if one is not willing to say that God can do anything that’s logically possible, because one says that suicide is logically possible but God cannot do it, instead opting for some view like that God is the first cause in all possible worlds, or that God can do anything that it is logically possible that God can do, vel caetera, as long as one maintains the paradigm cases of omnipotence from the tradition, one might be just clarifying.
But the Christian tradition, I claim, sees two particularly impressive and noteworthy cases of omniscience–knowing what is in the depths of the human heart and knowing future contingents. It is impressive that God knows how many hairs I have. But that is something that creatures can figure out, too. It is impressive that God knows all mathematical theorems. But since a theorem is, by definition, provable, a creature could in principle know it. These kinds of knowledge, while impressive, are not very different from the knowledge that creatures we have. But the tradition, I think, takes knowledge of the contents of our mind, as well as knowledge of future contingents, to be the paradigm impressive examples of omniscience.
If one does not save paradigm cases like these, one has not clarified the traditional understanding of omniscience but one has rejected it. This is so even if one says: “God knows everything that is true”, but denies that there are true non-tautological propositions about the future. If one does that, then one is no more a believer in omniscience, than someone who thinks God can do everything logically possible but who denies that creation is possible is a believer in omnipotence.

Open Theism and Divine Freedom
August 26, 2008 — 21:35

Author: Jeremy Pierce  Category: Atheism & Agnosticism Concept of God Divine Foreknowledge Free Will Open Theism  Comments: 15

[Cross-posted at Parableman] Open theists distinguish between two different varieties of their view. There are actually a number of ways to divide up open theism into varieties, but one particular division that open theists make among themselves is between the following two positions:
1. There is no such thing as a future to be known, and that’s why God doesn’t know the future exhaustively. It’s not a limitation on God that he doesn’t know everything that will happen. There’s nothing to be known, so God can’t know it. So God is omniscient in knowing all the facts about the future. There just aren’t very much such facts yet.
2. God could know the future, but it would prevent our freedom, so God chooses to limit his knowledge, knowing that knowledge about what we would choose to do would make us unfree. God doesn’t know all he could know metaphysically, but he does know all he could know given his choice not to know future free choices.
I’m not really sure these are distinct views.


Prophecy in Harry Potter
August 7, 2008 — 9:39

Author: Jeremy Pierce  Category: Christian Theology Concept of God Divine Foreknowledge Divine Providence Free Will Molinism Open Theism Theological Fatalism  Comments: 12

[cross-posted at Parableman]
I’m working on a chapter for the forthcoming Blackwell Philosophy and Harry Potter on the topic of destiny, and one of the things I’m trying to do in the chapter is distinguish between different metaphysical analyses of prophecy. I’ve come up with three, and I’m inclined to think that it might be exhaustive enough for the purposes of a popular-level work like this, but I’m curious if anyone here can think of any others.
Here’s what I’ve got (and how I’m presenting it in the draft I’m writing):
1. They involve mere likelihoods. No one has access to the actual future, but someone might have magical access to information that’s derived from what’s likely. Given what’s true about the various people involved, it’s very likely that a certain outcome will happen. That means prophecies, even the ones Dumbledore is inclined to call genuine, are not infallible. They can turn out get it wrong.
2. They do not derive their content from the actual future. Rather, they make the future happen. When a genuine prophecy occurs, it influences those who hear it in such a way that they end up doing things that will fulfill the prophecy. This kind of prophecy is self-fulfilling in a very literal sense.
3. The seer has some intuitive connection with the way things will really happen, such that the words of the prophecy are true about a future that really will be that way. If it’s a genuine prophecy, it can’t be wrong, because its origin lies in the very future events that it tells about. In the same way that a report about the past can bring knowledge about the past only if there’s some reliable connection with the actual events in the past, a genuine prophecy in this sense must derive its truth from a reliable method of getting facts about the future.
My understanding of J.K. Rowling’s view of prophecy, judging by this interview and my sense that the Albus Dumbledore character represents her views when he discusses this issue with Harry Potter, is that she wants to treat Professor Trelawney’s two genuine prophecies as the first kind, a kind of prophecy an open theist could accept.
There are hints in at least two of Dumbledore’s conversations with Harry that he thinks something like the second kind is going on, but it’s clearly not a reduction of prophecy to what happens in #2, because the characters in question (mostly Lord Voldemort) still make free choices and aren’t simply caused by the prophecy to do anything the way some ancients thought Laius was caused by Apollo’s prophecy to do what he did that led to Oedipus eventually killing him.
My argument at this point is that there isn’t really a way for Dumbledore to distinguish between Trelawney’s two genuine prophecies and all her vague predictions that can often be interpreted as coming true unless the genuine ones are of the third kind (because the pseudo-prophecies are of the first kind, and the genuine ones can’t be completely explained by the second kind). Rowling doesn’t seem to want to accept that, and Dumbledore is clearly with her, so there’s a consistency issue here both for the character and the author. But my argument depends on the options I’ve listed being exhaustive. Is that true?

Open Theism and Promises
November 1, 2007 — 20:16

Author: Alexander Pruss  Category: Open Theism  Tags:   Comments: 21

Thesis: If Open Theism is true, then either possibly there are some things some humans know that God doesn't know or possibly God has some false beliefs.  The conclusion is absurd, hence we should reject Open Theism.


For simplicity I will abbreviate "x does not fulfill the promise P and nothing prevents x from keeping P, nor does x conclude a defeater arises, nor does x forget" as "x violates P". 

  1. Let x and y be humans.  Often when x knows y's character to be solid and knows y to have promised to do something for x, x is not only justified in believing y will not violate the promise, but x knows it.
  2. If Open Theism holds, there is no possible divine doxastic policy such that, necessarily: (In every case like the one described in (1), God believes y will not violate the promise, and God has no false beliefs).
  3. Therefore, whatever possible divine doxastic policy is adopted, either in some worlds there will be a situation like that described in (1) where x knows y will not violate the promise, but God doesn't believe it and hence doesn't know it, or in some worlds God will have a false belief.
  4. This is absurd, and so Open Theism should be rejected.

Moreover, it is very likely that in the actual world either there are going to be cases of (1) where God doesn't know y will not violate the promise, or cases where God has some false belief.  For there are so many cases of (1) in the actual world, that it is highly likely that any divine doxastic policy that doesn't involve foreknowledge of free actions will either miss some cases of (1) or will lead to belief in some cases where y in fact violates the promise.