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#585 The Laws of Logic and the Cosmological Argument

July 01, 2018

Hello Dr. Criag. As a Christian, I am very thankful for your work. My question is on the laws of logic and the cosmological argument. If you say that from a naturalistic perspective something can come from nothing by nothing, then we know that you are breaking the laws of logic. But if there was nothing, including no logic, Then is it possible that something as impossible as a universe from nothing by nothing can happen because there were no laws of logic to break?. It seems like to me you have to prove the laws of logic are eternal before you can use the cosmological argument. Thanks again and God bless.


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Dr. craig’s response


Your question evinces a number of confusions, Daniel. I think it’s worth addressing these, since they seem to be not uncommon among hoi polloi on the Internet.

To begin with, I do not claim that the assertion that “something can come from nothing by nothing” breaks the laws of logic. To the contrary, I have affirmed that the denial of the causal principle is not strictly logically impossible.  Rather, the causal principle that Everything that begins to exist has a cause is, in my view, a metaphysically necessary truth whose denial is strictly logically possible, though unactualizable. So one should not charge the naturalist who denies this principle by saying the universe came from nothing with breaking the laws of logic.

Second, there seems to be a confusion about the ontological status of the laws of logic. You seem to assume that there must exist some objects, some things, which the expression “the laws of logic” refers to. That is quite unjustified. We often use such expressions in sentences we take to be true without thinking that they refer to real objects in the world, e.g., “the accident that was prevented,” “the hole in your shirt,” “the lack of compassion in the world,” “the sake of the children,” “the threatened strike,” etc.

I don’t think that there are any such things, any such objects, as the laws of logic. The laws of logic are simply a way of codifying inferences like “Necessarily, if John is fat and Mary is slim, then John is fat.” We codify this as the Rule of Inference called Simplification (symbolized as P&Q; therefore, P). There isn’t any such thing as Simplification; it’s just a valid way of inferential reasoning.

Now if you do think that the laws of logic do exist, then they must be abstract objects of some sort, presumably propositions, since they have a truth value. As such, they would exist timelessly and spacelessly, since they are not dependent upon physical objects. They would therefore be exempt from the causal principle, since they never began to exist.

Now sometimes people untutored in logic will say, “You can’t extrapolate the laws of logic beyond our universe. They hold in our universe, but you can’t assume that they apply beyond it, so as to infer a cause of the universe.” Notice how radical such a claim is: the objector is not denying the truth of the causal principle; rather he is denying that from the truths that “Everything that begins to exist has a cause” and “The universe began to exist,” one may validly infer that “The universe has a cause.” He admits that those statements are true; but he denies the logical Rule of Inference known as modus ponens (symbolically, P → Q; P; therefore Q). He claims that the validity of this inference is restricted to our universe; beyond it that inference cannot be validly made.

I trust that it is obvious that the objector has here an enormous burden of proof. He has to prove that the laws of logic somehow depend on our physical universe. That seems obviously false. I suspect that those who press this objection don’t understand what logic is.  Logic, as a purely formal discipline, is devoid of any empirical content and so is utterly independent of physical things. It is in that respect like mathematics. Given the definitions of “2,” “+,” “=,” and “4,” it is necessarily true that 2+2=4. Similarly, given the meanings of “&” and “→,” it is necessarily true that P&Q → P. The universe has nothing to do with it. Indeed, one branch of logic is so-called modal logic, which enables us to draw inferences about what is the case in other possible worlds. The objector would invalidate a whole branch of logic just to avoid the inference to theism.

I don’t think sceptics who press this objection fully realize where the objection leaves them. It implies that atheism (or agnosticism) is literally illogical. The objector concedes that it is the theistic view that follows logically from the accepted premises. In order to avoid it, you have to deny the laws of logic. Atheism is therefore illogical, since, according to this objection, it is founded on denying the logical Rules of Inference like modus ponens. This ought to make atheists extremely uncomfortable. It turns out that believers are really the logical thinkers after all.

Finally, the objector’s position is self-defeating. For how will he justify restricting the laws of logic to our universe? Any justification will have to involve assuming a transcendent perspective and reasoning about our universe. But it is just such reasoning that the objection prohibits. For example, suppose the objector says, “The laws of logic were invented by human beings. Therefore, they have no applicability beyond the universe.” On the objector’s view that inference holds only in our universe and says nothing about what holds beyond our universe. He cannot justifiably affirm that the laws of logic do not apply beyond our universe. Any attempt to justify the objection is thus self-defeating.

- William Lane Craig