Wednesday, November 22, 2006

Does Divine Timelessness Imply a B-Theory of Time?

Linda Zagzebski thinks not. In her book The Dilemma of Freedom and Foreknowledge, she argues that the classical doctrine of divine timelessness is compatible with an A-theory of time. She begins by laying out her understanding of the B-theory of time in terms of four theses, and then argues that denials of at least the first three theses are compatible with divine timelessness. The four theses are (p. 46):
  1. At every moment of time t, all events past, present, and future relative to t are equally real.
  2. The B-relations (i.e., earlier than, simultaneous with, and later than) are ontologically more basic than the A-properties (i.e., past, present, and future), which are reducible to B-relations.
  3. Temporal becoming is purely subjective.
  4. All true propositions can be fully expressed without using A-properties. Tenses and temporal indexicals are eliminable.
I've reworded her theses a bit for precision's sake. With the exception of (4), this is a fairly noncontroversial explication of the B-theory of time. (4) would be rejected by many B-theorists today. The standard line nowadays is to concede that tense in not eliminable but to maintain that tensed sentences can be given tenseless truth conditions.

Anyway, why might one think that divine timelessness entails a B-theory of time? Well, if God is essentially timeless and essentially omniscient (i.e., knowing all and only truths), then God's state of knowledge must be immutable, or unchanging. And since God is the perfect knower, it seems that God's perspective on things would have to the fundamentally correct or true perspective. So if God's sees all of history at once from the standpoint of eternity, then all of history must be realized at once from a timeless perspective, which is just what the B-theory of time states.

Zagzebski demurs, however. With regard to (1), she says (p. 48):
The A- and B-theories are competing theories about the status of events in some temporal observer's future. The A-theory maintains that events future relative to t are not real at t, while the B-theory maintains that events future relative to t are real at t. Tenet [(1)] is therefore a claim about the status of events relative to a time t. How events are related to a reference point outside of time is not part of either the A- or B-theories of time.
Her description of the difference between the A- and B-theories is mistaken, however. For one thing, her account of the A-theory is not consistent with all versions of the A-theory of time. That the future relative to a time t is not real at t is true for two versions of the A-theory, namely, presentism and the 'growing-block' theory, but it is not true for other versions, such as the 'moving spotlight' theory or Storrs McCall's branch attrition model. For another, it is false that either the A- or the B-theory aspires to be a theory of the status of events in some temporal observer's future. No. Each aspires to be a theory of reality from, as it were, a God's-eye perspective. In other words, each aspires to be a purely objective account of reality. Thus, whether or not they acknowledge the existence of God, B-theorists conceive of the temporal series as a static block because, so they think, if we could look at the temporal series from the outside, that's what it would look like. Advocates of divine timelessness agree, since they think God, who is outside of time, grasps the whole of time all at once, as though it were a static block.

Zagzebski responds to the charge that the proponents of divine timelessness is committed to theses (2) and (3) in much the same way (p. 50):
The view that Aquinas is committed to [(2)] and [(3)], like the view that he is committed to [(1)], founders on the assumption that the way temporal events look from an atemporal perspective implies something about the way they really are from a temporal perspective.
But again, the issue is not a matter of how events look from a temporal perspective, but how they really are. According to the A-theorist, temporal becoming is objective, such that from a God's-eye view of things the set of propositions that are true as of time t is not the same as the set of propositions that is true as of all other times. In particular, for the A-theorist there is an objective fact of the matter as to what time it is now. Thus, God, if he is omniscient, must know that fact. According to the B-theorist, however, temporal becoming is subjective, such that from a God's-eye view of things the set of propositions that are true as of any time is identical to the set of propositions that are true as of every other time. Truth, in short, is timeless, so there is no point (indeed it is positively misleading) on the B-theorist's view to even talk about truth at a time or of what is true as of a time.

As for thesis (4), Zagzebski initially concedes it. If God is omniscient, then he knows all and only truths. If there were ineliminably tensed true propositions, then he would have to know them. But then God couldn't be timeless because to know such propositions would mean that God's state of knowledge must be characterized by an ever-changing knowledge of what time it is now. Because she thinks God is timeless, Zagzebski concludes that (4) must be true. But if that's the end of the story, then the B-theory wins. Since truth supervenes on being, if all true propositions are fundamentally tenseless, then all of reality must be fundamentally tenseless.

To avoid this consequence, Zagzebski has two suggestions. The first is that God's knowledge may be nonpropositional, in other words, that God's knowledge simply consists in an intuition of all of reality. I'm sympathetic to this view of God's knowledge, but I don't see how it helps. If the A-theory of time is true, then there are tensed facts and an objective now. Consequently, God's intuition of reality would have to be internally tensed, and, since the referent of 'now' is continually changing, the content of God's intuition would have to change with it, which is incompatible with divine timelessness.

Zabzebski's second suggestion is to shift to a relativized conception of truth (p. 53):
If both the temporal and atemporal modes of being are ontologically real, it may turn out that propositions true from one perspective are nontrue from the other. The truth of a proposition would be relative to a perspective on this view. So even if tenet [(4)] is false and tenses are not eliminable from propositions expressing truths from the temporal perspective, such propositions are not true from the atemporal perspective and, hence, it is no problem that God does not know them.
Now I must confess that I find this suggestion to be very problematic. Consider the claim that "the truth of a proposition is relative to a perspective". Is that claim true? If not, then this suggestion immediately collapses. If it is true, however, then we must ask from which perspective, the temporal or atemporal one? If the answer is from both, then truth isn't relative to perspectives after all because the same principle applies equally to all perspectives. If the answer is from one but not the other, and if the A-theory is correct and tense is objective, then an atemporal God's knowledge of creation would be out of sync with creation, which means that he would't really have knowledge of creation, but only knowledge of his perspective on creation.

I conclude, then, that Zagzebski's attempt to reconcile divine timelessness with an A-theory of time fails. The primary reason for this failure is that she does not properly locate the dispute between the A- and B-theorist.

1 Comments:

At 2/22/2007 8:28 AM, Blogger Andrew Thomas said...

Interesting.

I have a blog on this myself which you might enjoy: The Big Brother Universe.

Firstly, I refer to the "A-series" as "tensed time" and the "B-Series" as "tenseless time". I consider the situation for beings inside a computer simulation. In that case, the "Grand Simulator" would have a current representation of the simulation for a particular "now" value which he would select. This would indicate a preference for tensed time (the A-Series). This would basically be the current state of the simulation as contained in your microprocessor's states. Why should be simulation use tenseless time (the B-Series) which would involve keeping track of events at ALL times? If you equate the "Grand Simulator" with "God" then I would agree with Linda Zagzebski that the tensed theory (the A-Series) is more likely.

All this is descibed in much greater detail in my blog.

 

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