(December 3, 2015 at 6:18 pm)athrock Wrote: 1. If objective moral values and duties do not exist, then God does not exist.
2. Objective moral values and duties do exist.
3. Therefore, God exists.
(December 5, 2015 at 1:06 pm)athrock Wrote:(December 4, 2015 at 9:22 am)Quantum Wrote: That logic is simply wrong.
The way you have written 1., you can only conclude from it that IF God exists, THEN there are objectIve morals. Not the reverse.
Are you certain of this?
I'm not saying I am 100% certain because I'm not trained in logic (having only one course in college), but all the questions raised in this thread have sent me googling for a refresher. I can't link to the site but if I understood what I read correctly, Hotmath.com explains that the contrapositive of a true statement is also true.
If P, then Q. TRUE
If not Q, then not P. TRUE
So, in the moral argument:
If God exists (P), then objective moral values and duties exist (Q).
If objective moral values and duties do not exist (not Q), then God does not exist (not P).
One other point that sort of tips me in the direction of thinking that the logic of the argument in the OP is valid is that IF IT WEREN'T, theists wouldn't even bother making the argument in the first place, because atheists wouldn't tolerate it.
Therefore, I'm inclined to believe that the logic is valid. The real questions concern the definitions of the terms and the premises themselves.
You could just look up denying the antecedent and comparing it to your argument.
Quote:Denying the antecedent, sometimes also called inverse error or fallacy of the inverse, is a formal fallacy of inferring the inverse from the original statement. It is committed by reasoning in the form:
If P, then Q.
Not P.
Therefore, not Q.
Wikipedia | Denying the antecedent
Your logic is wrong. The proper form of the argument is:
If God does not exist, then objective moral values do not exist;
Objective moral values exist;
Therefore God Exists.