Clarifying the Argument from Contingency

The argument from contingency1 has, for some people, one particular premise that is a bit hard to swallow. Additionally, this particular premise has an aspect to it that can make things a little confusing (it was a bit confusing for me when I first delved into it and I’ve seen it confuse others as well)2. Let’s look at the whole argument and then evaluate the challenging premise in a little more detail.

1. Everything that exists has an explanation of its existence, either in the necessity of its own nature or in an external cause.
2. If the universe3 has an explanation of its existence, that explanation is God.
3. The universe exists.
4. Therefore, the universe has an explanation of its existence. (1 & 3)
5. Therefore, the explanation of the existence of the universe is God. (2 & 4)

Premise 4 follows logically from 1 and 3. This is unsurprising.
Premise 5 follows logically from 2 and 4. Again, this is unsurprising.
Premise 3 is relatively uncontroversial, so we are left with premises 1 and 2.

Premise 1 is challenged by some people, but that approach is generally an attack on the principle of sufficient reason, and that’s not the topic of this post. Perhaps it will be a topic for a future post, but we won’t be addressing that today.

This leaves us with premise 2. This premise, for a lot of people, is a bit difficult to accept. However, if we look at the premise with a bit more of a critical eye, maybe it will be easier to understand and accept. Here’s the premise again:

2. If the universe has an explanation of its existence, that explanation is God.

Let’s change the wording just a bit:

2′.4 If the universe has an explanation of its existence, then atheism is not true. 5

Without diving into the details of what atheism means6 means at the philosophical and/or popular level (for the sake of keeping this post short), we are just changing the wording of the consequent 7 to read “then atheism is not true,” which is to say that God exists. This is pretty straightforward.

We need to examine the consequent of 2’ to clarify things just a bit more.

• If atheism is not true, then God exists.

Now we’ll flip the logic in the statement8:

• If atheism is true, then God does not exist.

Do you see what was done? We moved the negation to the consequent. We can do this in this particular instance because the statements are logically equivalent.9

Now that we’ve clarified the latter part of premise 2, let’s put the whole premise back together with the equivalences compared. Here’s the original premise again:

2. If the universe has an explanation of its existence, that explanation is God.

We’ll change the consequent:

2′. If the universe has an explanation of its existence, then atheism is not true.

We have to be careful with the rules of logic to make the statement logically equivalent:

2”. If atheism is true, then the universe has no explanation of its existence.

Premise 2’’ is logically equivalent to Premise 2.

It is this logical equivalence that has lead some atheists to say that the universe has no explanation. If the atheist admits to an explanation of the universe (Premise 1) then they are implicitly agreeing to Premise 2. The atheist is logically “arm twisted” into denying an explanation for the universe.

Hopefully this clears things up for some people.

Dr. William Lane Craig has a section in his book ON GUARD that expounds on this clarification and the entire argument in more detail. You can purchase his book here: Link.