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


Dear Dr. Craig,

In the Leibniz' Contingency Argument , the premise 2 states that "If the universe has an explanation of its existence, that explanation is God". This requires that the universe does not exist by the necessity of its own nature, and that anything that could possibly exist outside the universe, could not be the cause of the universe, except for God.

The universe is further defined as all of space-time reality, including all matter and energy. You have previously answered the question "Is Part of the Universe a Necessary Being?" (Question #235), essentially by stating that it would be absurd to suggest that a specific set of elementary particles would exist necessarily in all possible worlds, while being the cause of all the other similar particles.

It is surely absurd to suggest that any particular particles could possibly act as a universal cause for the whole physical reality. However, here you have not commented in any way to two more universal aspects of the universe. Now we come to the first candidate:

(1) Could the fundamental fabric of space-time reality exist by the necessity of its own nature? This would be the analogue of quantum fields in a final theory of everything.

This line of reasoning sounds to me very much like the thinking of Stephen Hawking (as in Question #180). You would clearly argue with the lines of the Kalam Cosmological Argument, that the space-time had a beginning in time, and must thus be contingent. So if the space-time fabric had a beginning, we still need an immaterial, necessarily existing cause, outside physical space and time.

It is argued that the list of conceivable entities existing beyond the space-time reality contains only abstract objects and God. Furthermore, abstract objects, such as the number seven, don't stand in causal relationships. The number seven has never caused any event in the universe (apart from the people thinking about the number seven). So it seems that abstract objects can not possibly be an intelligible cause of the space-time reality. But now we come to second candidate:

(2) Could the fundamental law(s) of nature exist by the necessity of its own nature? And could they be the cause of the existence of all space-time universe, including all matter and energy?

Laws of nature are not composed of a set of fundamental particles, certainly not in the way molecules or galaxies are. A truly fundamental law would be the same everywhere and always. A platonist might be happy to say that this kind of a law exist in the platonic heaven with the rules of geometry, mathematics and logic. It doesn't seem so absurd to propose that such a law could hold in every possible world, even in the absence of particles which would be affected by it.

What makes the laws of nature different from many abstract entities, such as numbers and sets, is that they certainly do have causal effects. The first law of Newton is the cause for an asteroid keeping its inertia and not slowing down in empty space. If the law of gravity didn't hold, most events in the history of the universe wouldn't have happened!

So it seems like the stock answers for either physical entities of abstract objects wouldn't apply for laws of nature. But is the final Law of Everything a viable alternative for God?

Thank you for your remarkable work and your clarity of thought!

PS. It was a pleasure to meet you at lunch after the debate with Kari Enqvist.



Dr. William Lane Craig’s Response

Dr. William Lane Craig

Your suggestions serve to advance the discussion, Otto, and are therefore valuable.

1. “Could the fundamental fabric of space-time reality exist by the necessity of its own nature?” Of course, the atheist could say that, but such a suggestion is, I think, unscientific and implausible. Spacetime seems to be contingent in its properties, and different models of the universe feature different spacetime structures. For example, some have a beginning and some don’t; some extend forever and some come to an end. Hawking recognizes that his proposed model is just one of many possible spacetimes. So our spacetime is plausibly not a necessary being.

2. “Could the fundamental law(s) of nature exist by the necessity of its own nature?” Yes, if you’re a Platonist! For such laws are mathematical equations, which are paradigmatic abstract objects. Such objects are thought by Platonists to exist necessarily. The question for the Platonist is not why such objects exist but why they are true. (Compare Hawking’s remark, “What puts the fire in the equations?”) On Platonism even false laws of nature exist necessarily as mathematical objects. They differ from the actual laws (that is, those that describe the actual world) in their truth value, the actual laws being true and these other laws being false.

But here’s the thing: as mathematical objects the laws of nature are causally effete. They have no causal powers and so cannot be the cause of anything. The idea that nature’s laws cause things is a misconception that is very widespread, even among professional scientists. They seem to have forgotten that laws are just mathematical objects which may be either true or false, depending on whether they are descriptive of the actual world or not, but they don’t determine which world is actual. On the contrary, which world is actual is explanatorily prior to which laws are true or false.

You say, “If the law of gravity didn't hold, most events in the history of the universe wouldn't have happened!” Right! If the law were not true, then the history of the universe would be different. That’s a true counterfactual conditional. But that doesn’t imply explanatory priority. Newton’s law doesn’t cause the world be the way it is; it has never been causally connected to any asteroid!

So as abstract objects, the laws of nature, while good candidates for necessarily existing entities, cannot explain why the contingent universe exists.

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