Saturday, May 10, 2014

Pruss on God's knowledge of the past

Commenting on a post of mine, Dr. Pruss draws attention to an interesting symmetry between God's knowledge of the future and the past:

Alexander R Pruss5/09/2014 6:00 PM 
I think it is deeply puzzling how God knows our future free choices. But it is no more puzzling than the deeply puzzling question of how God knows our past free choices. The problem in both cases is this: How can our actions affect the beliefs of a transcendent being? Whether our actions are in the past or in the future makes no difference here. 
(Now, granted, on growing block theories there is a difference, in that past actions and past persons (if there are any persons who don't exist forever) are real and future ones aren't. But on both presentism and eternalism there is ontological symmetry between past actions/persons and future actions/persons. And growing block is false. :-) )
I believe he's alluding to divine impassibility, which Brian Davies defines as "not able to be causally modified by an external agent," "God cannot be altered by anything a creature does." 
To flesh this out, I think Pruss is suggesting a paradoxical trilemma:
i) Humans have libertarian freedom
ii) God is impassible (i.e. can't be affected by the world)
iii) God knows our past and future choices
I say that's a paradoxical trilemma because Pruss presumably affirms the truth of all three propositions.
In reponse:
1. A Calvinist will relieve the trilemma by denying (i). 
From my perspective, it's a false trilemma. 
2. Jerry Walls will relieve the trilemma by denying (ii-iii). 
3. Where revealed truths generate an apparent contradiction, I think appeal to mystery or paradox is legit. That's an argument from authority (revelation), which is legit so long as the authority is legit. 
But I don't think human libertarian freedom is a revealed truth. At best, it's a philosophical construct. So it can't take refuge in an argument from authority. It stands or falls at the bar of reason. 
Worse, I think human libertarian freedom contradicts revealed truths regarding predestination, meticulous providence, divine hardening, &c.

In Calvinism, God knows our past and future choices because he predestined them. That doesn't generate any tension with impassibility, for God is affecting the creature, rather than vice versa. 


  1. Even on Calvinism we have the problem of how God knows what he decided to do. God's decisions are contingent. Do they affect God? Then we seem to get a violation of immutability or at least simplicity. An extrinsic model of divine beliefs, on which his beliefs about contingent things are partly constituted by the contingent truths, solves all the problems.

    1. If those contingent truths are dependent on what humans will freely do (in the libertarian sense), then isn't God's knowledge (of those contingent truths) affected by our choices (pace impassibility)?

    2. Seems to me that you're now resorting to an idiosyncratic definition of impassibility. That's why I quoted from Brian Davies (the 3rd ed. of his intro to the philosophy of religion, p5).

      So you're shifting ground from your original argument.

      The fact that God's knowledge of his own decisions is "contingent" on his own decisions is entirely consistent with God being unaffected by the *world*.

      And in what sense would he be *affected* by knowing what he decided to do? It's not as if there's a shift between prior ignorance and subsequent knowledge. If God is timeless, it's not even that he knew what he was going to decide before he made his decision. Rather, there was no prior state or prior moment of indecision in the first place. So God hasn't undergone any change by that relation.

    3. How is a violation of simplicity equivalent to a violation of impassibility?

    4. On the face of it, doesn't your statement that God's decisions are contingent violate divine simplicity? Given divine simplicity, aren't God's decisions as essential or necessary as God in himself?

    5. It's true that those who are Calvinists in the strongest sense of thinking that we have no alternate possibilities ever (one could be a Calvinist in a weaker sense of thinking that we have no alternate possibilities with respect to salvation, but we have alternate possibilities with respect to less significant actions) don't have the impassibility problem. But Calvinists still have the problem that they have to admit that there is an order of explanation in God, even if not of time: first in the order of explanation comes a contingent divine decision (unless one takes Edwards' view that God's own actions are determined--which leads to trouble for omnipotence and God's sovereignty over his own actions) and then comes his belief that he has so decided.

      Likewise, Calvinists who, like Calvin and Turretin, believe in divine simplicity -- and there is certainly good reason for them to do so -- will still have the problem.

      On contingent divine decisions and divine simplicity, see:

    6. I disagree with Edwards on that point. However, doesn't simplicity have the same consequences?

      If God is actus purus, if there's no unrealized potentialities in God, then aren't all divine decisions and actions necessary/necessitated?

      Likewise, if even divine decisions or actions are identical with God's essence, then God has no contingent relations, but only essential relations. So, once again, aren't all divine decisions and actions necessary/necessitated?

  2. Since on Calvinism God's knowledge of contingent events is eternal self-knowledge of his sovereign will, how does this violate his immutability?

    "An extrinsic model of divine beliefs, on which his beliefs about contingent things are partly constituted by the contingent truths, solves all the problems."

    But wouldn't the extrinsic model call into question a strong version of divine aseity?

  3. Is there much of a biblical basis for divine impassibility? I've heard Acts 14:15 being quoted in support of it, but that seems to turn on the KJV using "passions," whereas newer translations seem to favour "nature" - which, I think has different connotations.

    I suppose there's always Malachi 3:6...if God doesn't change, then it seems unlikely that He could be affected by the world and the events therein. Thoughts?

    1. The definition I quoted does not define impassibility in reference to divine emotion ("passions"). That's a separate issue.

  4. "Worse, I think human libertarian freedom contradicts revealed truths regarding predestination, meticulous providence, divine hardening, &c."

    There's the rub. I think Paul had something like this in mind when he was upbraiding the church in Corinth for their love for and undue elevation of worldly pseudo-wisdom over and against the simple revealed truth of Christ and Him crucified.

    Human wisdom set against divine revelation is an old, old problem for fallen man.

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    1. According to Jonathan Edwards there are no contingent truths for God.

      //Propositions about future contingents can't be self-evident, however, because the states of affairs they represent are neither present to the mind nor necessary. But they can't be proved either, for if the state of affairs expressed by the proposition is genuinely contingent, “there is nothing now existent with which the future existence of the contingent event is [necessarily] connected.” Future contingents are thus necessarily unknowable (Freedom of the Will, 1754; Edwards 1957–, vol. 1, 259). Since God's knowledge of the future is comprehensive, it follows that no future event (and so no future human action) is genuinely contingent.//

      In other words, Dr. Pruss' objection above stands [IMO] for the compatibilist as far as I can tell.

    2. Pruss' objection isn't indexed to "future contingents," especially in the sense Edwards meant it. Of course, in Edwards' (nuanced) sense, most Calvinists would agree that there are no contingents, so it's not an objection to the system to state propositions of the system. For Edwards, a true (as opposed to a 'common' understanding of the term, which Edwards allowed for) contingency had no reason for its existence; moreover, it could not be known with certainty. In any case, the upshot here is that the employment of Edwards is completely otiose for the purposes you seem to want to put it. (And let's also bear in mind that Calvinism accepts the *project* of theological determinism, but this doesn't entail that all *models* of theological determinism are correct. That is, even if you could use Edwards to drive a wedge between standard arguments against the compatibility of LFW and omniscience on the one hand, and theological determinist commitments on the other, that won't suffice to show that there is indeed such a tension, as Calvinists are free to reject particular troublesome *models* of theological determinism—indeed, just as libertarians do when it comes to *models* of divine knowledge vis-a-vis God's knowledge of future LFW choices).

  6. When Pruss wrote, "God's decisions are contingent. Do they affect God? Then we seem to get a violation of immutability or at least simplicity." I took that to mean God is free to do X and these decisions affect God. In other words, God is free but it seems this freedom impacts His "immutability or at least simplicity." The only way I see a way around this [in light of how I have come to understand compatibilism] is Edwards assessment of contingency as a whole.

    1. How would God's decisions affect God? He didn't change his mind.

    2. Seems to me the issue wasn't divine freedom, but human freedom in relation to divine foreknowledge and impassibility.