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#721 Logic and God

February 28, 2021

Hello, Dr. Craig!

I am currently a student at seminary pursuing a Master of Arts in Philosophy, and God led me down this course through a crisis of faith in high school that led me to your debates and lectures on YouTube. In other words, I have you to thank both for my interest in philosophy and for God's work to save and strengthen my faith in high school. I am eternally grateful.

I have a question about a phrase that I've heard and affirm but find troubling. It is often said that all truth is grounded in God, and while I believe that this statement is true, it seems awfully ambiguous. For instance, it seems right to say that logic is grounded in God's nature, but how can we interpret that statement sensibly?

First, it seems like you'd have to interpret what it means to say that "logic" is grounded in God's nature. For the sake of convention, let's say that by "logic," we mean the propositions that we tend to place in logic as a field of inquiry (e.g., the truth of the law of non-contradiction or the validity of modus tollens).

Second, you'd have to interpret what it means to say that logic is "grounded in God's nature." This is particularly puzzling for me. There are at least two options that I can think of.

1. One could say that these propositions, as just one subset of all propositions, are grounded in God's nature in some way that applies to all abstract objects (if they exist). Perhaps absolute creationism would work here. This doesn't seem right to me for the reason that it seems that different kinds of propositions are grounded in God in different ways. For instance, true propositions about morality are grounded in God because His character is the standard for morality, but that isn't why the law of non-contradiction is grounded in God.

2. One could argue that God's mind is the standard for the truth of propositions in logic. Logic is merely a description of God's pattern of thought. This option seems analogous to the way in which true propositions about morality are grounded in God.

Furthermore, one rebuttal, that it's difficult to see why it isn't the case that God recognizes the laws of logic and just perfectly follows them in His thought, seems to work just as well in the case of propositions about morality. (Maybe you could pose a kind of "Euthyphro's Dilemma" about logic.) If successful, does this rebuttal undercut that response both in the case of morality and logic?

It does seem difficult to tell how one could distinguish between God's nature as the standard for morality and logic and God's perfect recognition of these standards. Do you find either option more plausible? Or, maybe there is some other option that I'm missing. I'd appreciate some help working out this ambiguity in my mind.

Thanks for your great work for the Kingdom of God!


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Dr. craig’s response


I’m thrilled, Kevin, to learn of your victory in your crisis of faith and now for your further studies! Your question is one that intrigues me but to which I’ve not devoted much thought. So I’ll just make a couple of suggestions in response to your questions.

Let’s accept that “logic” refers to what you say it does, principles that are studied by logicians, such as the rules of inference.

When it is said that “logic is grounded in God's nature,” I think that the main impulse is to reject some sort of theistic voluntarism that would ground logic in God’s will. For example, Brian Leftow’s massive God and Necessity (Oxford University Press, 2012) grounds some necessary truths in God’s nature and some in His will, placing the rules of logic in the former group. The idea here is that it’s not up to God what rules govern logical reasoning; these are independent of His will but reflect His nature.

I think you’re right that absolute creationism doesn’t get at the question before us. But I don’t think that’s because abstract objects are grounded in God in different ways. Whether moral truths are grounded in God’s character while logical truths are grounded in, say, God’s intellect doesn’t matter, for in both cases it is God’s nature that grounds them. Rather, it seems to me, the absolute creationist is trying to answer the ontological question of the existence of such propositions, whereas the question before us is about the truth value of the propositions. The ontological question arises only if you’re a realist about such abstract entities as propositions.

So your second point seems the germane point: “God's mind is the standard for the truth of propositions in logic.” Here your suggestion is that “Logic is merely a description of God's pattern of thought.” That seems to me very plausible. We codify how God naturally thinks into logical rules that, being grounded in His nature, are necessarily true.

As for the suggestion offered in rebuttal that “God recognizes the laws of logic and just perfectly follows them in His thought,” it seems to me that this amounts to nothing more than an alternative suggestion that denies that logic is grounded in God. I don’t see that that’s significant, since we’re not trying to give an argument that logic is grounded in God. We’re just trying to articulate the view. Someone is perfectly free to articulate an alternative view. We don’t need to be able to “distinguish” between these alternatives in the sense that one would appear different than the other; all we have to do is be able to individuate the two views by marking their differences. I think that’s easy: On the one view logic has a grounding, while on the other it doesn’t.

If we were to ask which view we should prefer, I think theists would prefer the view that God is the ground of logic because it extols His greatness. God is a maximally great being, and He seems greater if logic is grounded in His very nature rather than merely followed by Him. Moreover, the view that logic is grounded in God seems to have greater explanatory depth and is therefore to be preferred. On both views the rules of logic are necessarily true, but on the grounding view we have an explanation of that fact, while alternative has zero explanatory depth.

It seems to me that the case of logical truths and moral truths is quite parallel. In both cases, we want to know what grounds these necessary truths. In both cases, a good theistic answer is that they are grounded in different aspects of God’s nature.

- William Lane Craig