Does the B-theory of Time Exclude Human Freedom?

This is the weekly Q & A blog post by our Research Professor in Philosophy, Dr. William Lane Craig.

Question

Dear Dr. Craig,

Thank you for your relentless study and work to communicate truth to the world. You have impacted my faith more than any other Christ follower in the world today. With that said, however, I am having a hard time with one of your recent statements. In your recent Q&A blog you made a comment that I reluctantly disagree with. In regards to the tenseless (B-theory) view of time and libertarian free will, you wrote the following:

“Now in fact I do not think that a tenseless theory of time is incompatible with free will. So long as causal determinism is false, it does not seem to matter so far as libertarian freedom is concerned whether one’s future choices exist. This takes us into very interesting discussions of divine foreknowledge of future free choices.”

My disagreement with you is regarding the claim that if the B-theory of time is true, then causal determinism is NOT false. That is to say, if the B-theory is reality, then causal determinism is true. In fact, just as the shape and structure of a slide at the water park determines the movement of the person traveling down the slide, the shape and structure of the 4-D block of spacetime causally determines the beliefs and behaviors of the “illusion of self-consciousness” traveling down the frozen “worm” in the static block. My argument is that these “choices” are purely illusory on a naturalistic B-theory model.

Dr. Craig, you rightly bring up the issue of divine foreknowledge and future free choices; however, I think this analogy is dissimilar. As you have taught me, knowledge (possessed by God or not) does not stand in causal relation with anything. For example, an infallible weather barometer that knew with 100 percent certainty that it will rain in Spain tomorrow does not cause the rain in Spain tomorrow.

However, on the B-theory model, the shape and structure of the eternal and static block does causally determine the beliefs and behaviors of the “person” who is nothing more than a slice of a frozen worm in the static block. Consider my water park analogy again: if the shape of the slide veers to the left, you could not go to the right even if you wanted to. Similarly, if the frozen worm in the static block veers to the left, the illusion of self-consciousness goes to the left no matter what. Therefore, this “choice” is nothing but an illusion if the B-theory of time is true (this would include the so-called “choice” to believe the B-theory is true).

If the eternal block of 4-D spacetime is reality, then not only does evolution not account for the biological complexity of primates “today” (complex primates are just as eternal as the eternal block), but the “choices” one makes have not *really* been based on deliberation and the process of reason. In fact, the so-called “choice” the slice of a worm has made has been frozen and static from eternity past and is just as old or ageless and eternal as the static block of 4-D spacetime itself.

Moreover, on eternal and static B-theory, so-called indeterminate events like particle decay – while not determined due to antecedent causal motion – are in fact nevertheless causally determined due to their indelible eternal inevitability built into the time-slice strata of the B-block. It seems to me that these “indeterminate events” don’t really “happen” on eternalism; rather, the event is just as eternal as the eternal block itself.

Dr. Craig, you are my hero and if it were not for your teachings regarding time theory, I would not disagree with you on this point. However, perhaps we don't really disagree after all because you did say, "So long as causal determinism is false..." My contention is simply that if a naturalistic B-theory model of time is true, then so is causal determinism.

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I am looking forward to seeing you at the EPS conference in a few days!

In Christ alone,

Tim

United States

Dr. William Lane Craig’s Response

It was good to see you at EPS, Tim! Thanks for your participation in our RF Local Chapters Directors’ meeting!

It’s quite understandable that one would think that the B-theory of time is incompatible with human freedom. After all, if your future free choices exist (tenselessly) just as really as your present and past choices, then aren’t they somehow fixed and beyond your control? Do you really have the ability to choose differently?

So to think, however, is to commit the same error as the theological fatalist, who thinks that God’s foreknowing what you will do is incompatible with human free choices.

First of all, let’s rid ourselves of the idea that the B-theory of time implies causal determinism and so is incompatible with human freedom. As B-theorist extraordinaire Adolf Grünbaum emphasized long ago, the B-theory does not imply that events which lie in our future are causally determined with respect to antecedent events.[1] Indeed, some such event could be wholly undetermined by antecedent causes. On any standard definition of libertarian freedom, therefore, such an event could be a genuinely free choice.

Your claim that “just as the shape and structure of a slide at the water park determines the movement of the person traveling down the slide, the shape and structure of the 4-D block of spacetime causally determines the beliefs and behaviors of the ‘illusion of self-consciousness’ traveling down the frozen ‘worm’ in the static block” gets things exactly backwards. It is I who by my free choices determine the shape and structure of the 4-D block of spacetime—at least in my vicinity. For example, by freely choosing rashly to pull out into busy traffic I determine that my spacetime worm comes to an abrupt end as it intersects the spacetime worm of a semi-trailer truck. I determine which way the worm will turn, and in that respect your waterslide analogy is faulty.

Now, of course, if you think of self-consciousness as a causally impotent epiphenomenon which just rides along on its physical brain states, then you’re right that we cannot freely determine our future temporal slices. But then the real culprit is one’s philosophy of mind, and I don’t see why the B-theorist can’t be a substance dualist who thinks that each temporal slice of the 4-D worm can freely determine future slices. Admittedly, this raises problems for personal identity over time, as I have argued, but again this is a different problem.

Second, when you go on to claim that “the so-called ‘choice’ the slice of a worm has made has been frozen and static from eternity past and is just as old or ageless and eternal as the static block of 4-D spacetime itself” and that “so-called indeterminate events like particle decay – while not determined due to antecedent causal motion – are in fact nevertheless causally determined due to their indelible eternal inevitability built into the time-slice strata of the B-block,” you are in danger of lapsing into fatalism. You’re right that the choice or quantum event is just as changeless and eternal as the 4-D block itself—indeed, they are part of that block—but when you infer that they are “inevitable,” you have made the same mistake as the person who thinks that our future choices are inevitable because God has infallibly foreknown them from eternity past. God’s foreknowledge is thus analogous to the B-theory of time. It is eternal and changeless and in that sense “frozen,” but that does not render the human choices foreknown by God inevitable. For although we cannot (by definition!) change the future, nevertheless we can act in such a way that if we were to act in that way God’s foreknowledge would have been different.

Similarly, on a B-theory of time, although we cannot change the future, we can act in such a way that if we were to act in that way, the future would be different. For example, when the time comes, I could decide not to pull out into traffic rashly but to wait for a gap when it would be safe to proceed. Even though, ex hypothesi, I will not make that choice, nevertheless I have the ability to make that choice, and were I to do so, my spacetime worm would not end where it does. Thus, while I do not have the ability to change the future, I have the ability to freely determine future.

So don’t infer from the tenseless existence of events in our future that such events are inevitable or necessary or in any way not free. And don’t think that because future events exist, they are somehow causally determined by the structure of 4-D spacetime. On the contrary, you by your free choices would determine in some small way the structure of 4-D spacetime.

The B-theory of time is beset with problems, but I don’t think denial of human freedom is one of them.