Disproving Odin - An Experiment in arguing with a theist with Theist logic

[SteveII]

For reference, the KCA:
1. Everything that begins to exist has a cause.
2. The universe began to exist.
3. Therefore, the universe has a cause.

Fallacious.

It fails with a affirming the consequent fallacy at the first premise.

Here's why:

Premise 1 makes the distinction between things that 'begin to exist', and things that 'don't begin to exist'. That is defining 2 sets, the set with everything that begins to exist, and the set of things that don't begin to exist.

If the only thing that you believe is in the set of things that don't begin to exist, is your god, then you are smuggling in your conclusion in the first premise.

KCA also has an equivocation fallacy in the 2nd premise. But since it fails on the 1st, there is no reason to continue.

This is affirming the consequent:

P implies Q
Q 
therefore P

Also called the fallacy of the converse. An example is:

1. If Bill Gates owns Fort Knox (P), then Bill Gates is rich (Q).
2. Bill Gates is rich. (Q)
3. Therefore, Bill Gates owns Fort Knox. (P)

This is the KCA

P implies Q 
P 
therefore Q

1. Everything that begins to exist (P) has a cause. (Q)
2. The universe began to exist. (P)
3. Therefore, the universe has a cause. (Q)

Nope. Definitely not Affirming the Consequent. 

You point out two possibilities: those things that don't begin to exist and those things that do. That is very simply put the distinction between something that is necessary and something that is contingent. You could insert the phrase "All contingent objects" in the Premise (1) and it would mean exactly the same thing. The universe by definition is a contingent object. The reason that Premise (1) is formulated that way is because necessary objects don't have a cause--so don't belong in Premise (1)