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

COSMOLOGICAL ARGUMENT My opponent objects to my word "explainable", saying it should instead read "capable of being understood". When something is capable of being explained, it is certainly capable of being understood, and vise versa. Therefore, I hold firmly that there was nothing wrong with my word swap. My opponent has this to say in regards to my objection of "rationally having to accept premise 2a" (premise 3): "If there is no initial explanation as to why the Universe exists, how can the universe exist without an initial explanation? [. .. ] Without an initial cause to the Universe, there is no universe. " This statement from my opponent is very telling, and by defending his premises with it, he has violated at least one logical fallacy: begging the question, special pleading, and/or argument from ignorance. My opponent wishes to say (as is clear from his last statement, without a cause how is there a universe? ) "Everything which exists has a cause", but knows he can't. This is because, as was pointed out in the first Cosmological argument constructed nearly 1,000 years ago, this creates the problem of "What caused God"? If you say "Nothing caused God", then you have violated Special Pleading, the logical fallacy of excluding something from the truth of one of your premises. Or, perhaps, he doesn't want us to rationally choose premise 2a because he already knows the universe's explanation if a personal one (ie, a deity). He uses the supposed truth of the conclusion to justify an otherwise unjustified premise. How does he know the conclusion and premise are valid if they only serve to justify each other (they are either true together or false together; how does he know they are true)? That is begging the question (circular reasoning). Furthermore, he asks us "How can the universe exist without an explanation? " This is as if to appeal to our intuition (another logical fallacy) instead of evidence. There is no evidence suggesting the universe had or needed to have an explanation. And there is no evidence for an explanation; however, my opponent here is appealing to this lack of knowledge of the origins of the universe to thread his own fictive one: an argument from ignorance. TELEOLOGICAL ARGUMENT Premise two: "Things that lack intelligence have a purpose. " I suspected my opponent of this logical fallacy, but waited to call him out on it until he plainly revealed himself. The fallacy my opponent violates now, ladies and gentlemen, is equivocation: using an ambiguous word (one with at least two meanings) in an argument without specifying the definition. In this case, that word is "purpose". My opponent says that magma has a "purpose", to allow tectonic shifts and volcanic activity. However, this only holds true if the definition of "purpose" is "the action in which a thing does by its very nature". Purposes such as these, as we know, are not necessarily given by intelligent beings. The "purpose" I was using (and the reason for my rewriting of his premises) was "the reason in which a thing was created or utilized". We cannot say for certain that magma was created specifically to allow tectonic shifting or that the Earth was created to suit life or that the universe was created for any purpose at all. Therefore, it cannot be said for certain that a deity exists.