The belief in the existence of a deity is logically valid.

COSMOLOGICAL ARGUMENT Premise one, as my opponent states: "Existence is only intelligible if it has an explanation. " When we swap "intelligible" with its synonym "explainable", we see just how absurdly axiomatic this premise really is: "Existence is only explainable if it has an explanation. " I agree with this premise. However, please carefully note that this is a conditional contention. Only IF existence has an explanation can it be explainable. Premise two: "The universes' existence is, therefore, one of two things: a) unintelligible (not explainable) b) has an explanation" I agree with this premise, assuming you meant "impossible to ever be intelligible" in the first scenario. Premise three: "A rational person cannot accept premise 2a by the definition of rationality. " This is where I find fault, and I remind you that the first premise was conditional. IF existence has an explanation, THEN we would be able to explain it (assuming we somehow knew the explanation). However, there is no reason to believe that the universe's existence necessarily has an explanation. Premise four: "A rational person must accept premise 2b, the universe has an explanation. " By extension of my last remark, I also find this premise untrue. Premise five: "There are 3 types of explanations: a) Scientific: physical conditions laws = an event b) Personal: Explanations citing desires, beliefs, powers and intentions of some personal agent. c) Essential: The essence of the thing to be explained necessitates its existence or qualities (for example, if you ask why a triangle has 3 sides, I would respond that it is the essence and necessity for a triangle to have 3 sides by its definition. " No comment. Premise six: "The explanation for the Universes entire existence cannot be scientific as there are no independent laws and physical conditions independent of what is being explained. " I find that there is absolutely no reason to believe this premise to be true either. For all my opponent or I know, there could be other physical universes outside of our own, citing M Theory as a basic example. Premise seven: "The Universes existence is not essential because the universe does not exist necessarily. " I also find no reason to believe this is true. You cited a triangle as an example, saying that it must have three sides because that is the very definition of a triangle. Following the same logic, the universe, by definition, must exist. A universe that doesn't exist is not a universe at all. Premise eight: "A rational person therefore, must believe the Universe has a personal explanation. " Premise nine: "No personal agent but, a deity could have created the entire universe. " Conclusion: "A rational person must believe a deity exists. " As extensions of previous objections, I find all three of the above statements to be false. TELEOLOGICAL ARGUMENT Premise one: "Some things lack intelligence" Agreed. Premise two: "Things that lack intelligence have a purpose" I find this untrue, unless it reads "Things that lack intelligence are given purposes". Premise three: "Something which lacks intelligence but, has a purpose must have something with intelligence guiding it" By extension of my previous comment, I find this untrue unless it reads "Something which lacks intelligence, but has been given a purpose, must have been given it by something intelligent". Conclusion: "There must be an intelligent being who oversees the Universe directing all unintelligent things to their purposes. " Even if the first three premises are true (as I rewrote them), this conclusion does not logically follow. I look forward to my opponent's responses.