Saturday, May 16, 2015

Mailbag: The Principle of Sufficient Reason and the Kalam

Today’s question is from Jon!

Jon writes: “Hi Randy,

I have a question I hope you could help me with regarding the first premise of the kalam argument. In his typical defense of the argument William Lane Craig often argues that if one denies the first premise and believes that the universe actually came in to being out of nothing, then it becomes inexplicable as to why anything and everything does not come in to being in this way.

It seems to me that Dr. Craig's argument rests on the assumption of Leibniz's principle of sufficient reason (PSR), that “no fact can be real or existent, no statement true, unless there be a sufficient reason why it is so and not otherwise” because we are asking what is the sufficient reason as to why only the universe came in to being from nothing. My question is the following: How can Dr. Craig consistently argue the point given that he doesn't accept Leibniz's own version of the PSR?

God bless,

Randy responds:

Hi Jon,

This is an interesting question! It seems to me that, at worst, it turns out the causal principle behind the kalam entails the strong version of the PSR, but it is not itself the reason for affirming it. One must look at Craig's reasons for affirming "Whatever begins to exist had a cause." (It's also worth noting his current formulation is "if the universe began to exist, then it had a transcendent cause.")

Craig often argues that, first, "It is based on the metaphysical intuition that something cannot come out of nothing. Hence, any argument for the principle is apt to be less obvious than the principle itself," which is metaphysical intuition. The second reason is that it would be inexplicable why it is not the case that just anything and everything comes into being uncaused. Thus, we see two reasons that are not themselves just identical to Leibniz's PSR; metaphysical intuition of being ("out of nothing, nothing comes") and "the way of negation" objection of observation of things not popping into being uncaused (as far as we know).

Now, you're certainly right that some kind of PSR is in use or otherwise entailed, but it's not quite Leibniz's version. The version Leibniz used extended even to statements and propositions, whereas Craig has a more modest PSR that claims that "anything that exists has an explanation of its existence, either in the necessity of its own nature or an external cause." This focus on existence works with propositions, even if they do exist, because their mere existence does not dictate their truth value, nor in virtue of what they are true.

The causal principle in the kalam, I think you can see, only addresses existence, and not the conditions for truth-value of propositions.

So, in short, I think Craig's reasons for affirming the causal premise are slightly different, and the PSR to which he is committed by the kalam is not identical to Leibniz's. Hope this helps! 

For more, I recommend checking out what Craig says on the PSR and on the kalam to clear it up!


  1. Is there a difference between a 'cause' and an 'explanation'? The terms seem to be often used interchangeably. For example, in WLC's contingency argument, premise 1 uses both terms as though they are equivalent.

    1. Hi Dennis, thanks for the question! Craig's version of the PSR states: "anything that exists has an explanation of its existence, either in the necessity of its own nature or an external cause." Here, then, I think we actually see "explanation" and "cause" are not identical.

      This is because God's nature isn't the cause of his existence (or at least, Craig and defenders of this PSR would most likely deny this, as would I). Thus, if God, serving as a paradigmatic example here, has his existence explained by the necessity of his own nature, then even though he is not caused to exist by any thing, event, state of affairs, etc., his necessary nature is still a sufficient explanation for such. Does that help?

    2. Can we say then that causes are a type of explanation? That is to say, is the principle of causation (i.e. all effects have causes) a subset of the PSR? Thus, an external cause could be an explanation for the existence of a contingent being, but not for God (for the reason you gave.)

    3. Yes, I think that may be the right way to look at it!


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