Over the course of the 10 months this subreddit has existed, and particularly in the past few days, there has been no topic more divisive than the cosmological argument. Clearly, any argument that concludes in God must be emotionally charged for theists and atheists alike. So, I present for your consideration a sub-part of the argument, which does not conclude in God or anything God-like:

1. Everything either:

   • Has a cause, or
     
   • Does not have a cause.
     

2. Nothing that has a cause is self-explaining. It is instead explained by its cause.

3. Chains of explanation cannot be infinite, because an infinite chain of explanation never actually gets to the point of explaining anything.

4. Therefore, all chains of explanation originate from something that is uncaused.

Here are my defenses of the premises:

(1) is just an axiom of logic. If something has a cause, then 1 is true. But if it is false that it has a cause, then it does not have a cause, so 1 is also true. There is no case where 1 can be false.

(2) is a fundamental tenet of scientific inquiry. Consider a scientist working in a lab. Some detectable effect is observed on an instrument. The scientist says "yes, this effect does have a cause, but I'm not interested in pursuing it - I consider the thing itself to be self-explaining." Surely this is nonsense.

(3) just says that if things with causes are not self-explaining, then an infinite number of things with causes is also not self-explaining. Adding an infinite number of zeroes together still equals zero.

(4) is logically entailed.

What do you think? Is this argument sound, within its limited scope?