TwoAbused Words: Rational and Coherent

I have noticed a trend on forums where the Theism/Atheism argument is raised to abuse two words. I personally believe that words in the English Language have precise meanings and that their definitions are immutable, save for colloquialisms, which have no place in debate. These words are: Rational, and Coherent. These abuses are seen equally often on both sides of the argument, which is to say that an Atheist is just as likely to wrongly declare irrationality as a Theist is to declare coherency, or vis versa.

Rational is perhaps the most abused of these words. People use it to indicate whether or not an idea or thesis is supported by the precepts of common knowledge upon a cursory examination. In a colloquial or informal context, that is in fact the acceptable use. However, in a philosophical discussion, however informal, the word rational takes on a whole new meaning. Here, Allison and Branden, first year philosophy students, are going to help demonstrate this point.

For example, Allison might say:

"I believe in the God of the Bible because I have had an apparition of Christ, and he told me he Truth of the Word.."

And then, Branden replies:

"That's irrational."

Branden is simultaneously right and wrong, which is an awkward state. What youtube user two has actually said, in a philosophical definition of rationality, is that Alice "came to that conclusion through a process which involved emotion, subjective analysis, or flawed logic." However, Alice had an apparition, in which Christ appeared to her, and told her he truth of the Gospel. If Bill Maher came before you, announced his name, and told you that his show was on HBO, unless you were an overly skeptical person, you wouldn't need to use emotion to determine if that was true (though it would change whether or not you liked his comedy). The statement "Real Time is on HBO" is objective, and the fact of it is not subject to a subjective analysis. There's no flawed logic in accepting something someone told you about their subject of expertise, though it's always wise to fact-check them. Therefore, under Philosophical terms, the decision to trust the apparition actually was rational. Branden's point was that trusting an apparition that couldn't be proved and could be the product of a mental illness seemed less than sound... but that's not what he said.

Further on in their conversation, Branden says:

"I don't believe a God is necessary for the appearance of human morality. Discounting that many humans do not behave altogether morally, morals are simply the project of group utility. Old morals like not killing, stealing, or raping are important because those three actions affect the strength of a pack, village, or other social construct."

And Alice's somewhat premature reply is:

"That's Incoherent." 

Coherency in philosophy has a very specific meaning. It means only that what position Branden has espoused must be consistent with all of his actual beliefs in order for it to be true (where true in this context refers not to Truth, but to the absence of a lie). An argument can be incoherent, but only if it contains an internal contradiction.