logic fallacy?

I'm feeling kinda stupid right now, because I can't come up with the phrase for this. It's the logical fallacy (I think it's an informal fallacy) when you say something along the lines of "X is obvious therefore it's true".

 

do you mean "Common Sense" ?

 

A logical fallacy is a justification or argument made on the basis of a preconception or assumption, it includes stuff like appeals to authority, appeals to emotion and straw-men arguments.
For example:
Person A: Metal halide bulbs are great for SPS.
Person B: Well, T5s and LEDs do just as good a job if not better using less energy!
-The isssue is that Person B has insinuated that Person A meant "only metal halide bulbs are good for SPS" instead of addressing his/her original claim.

 

You are thinking or inductive and deductive reasoning

In your example specifically I think it is deductive reasoning

 

Ah sorry, I thought you were asking what a logical fallacy is, as opposed to trying to describe a specific one. I think what you're describing is similar to an inductive fallacy.

 

It's an example of deductive reasoning.

The only animals with trunks are elephants. This animal has a trunk. It must be an elephant.

 

Related and possibly what you're looking for are the naturalistic fallacy arguing that a thing is good because it reflects the state of nature. Similar is the is-ought problem wherein one confuses what is with what should ideally be.

You could also think of this as a form of petitio principii, or begging the question in that you're asking to assume as true the issue in question.

 

It's deductive reasoning but not all deductive reasoning is a fallacy, for example, if axioms are properly used. So isn't it sort of a fallacy to label it deductive reasoning a fallacy Many formal fallacies though are the result of misguided deductive reasoning. These are deductive fallacies (such as Servillius's example), in which case someone is mistaking deductive validity for truth. The reason it is mistaken for truth, could be looked at as another sort of fallacy in itself, in this case probably something along the lines of argument ad populum, that is, appealing to, in this case a popular notion.

 

I was going for the specific name for "It's true because it's obvious.". I actually thought it would have a specific name ("appeal to DUH!", perhaps), but I guess not.

The "obviousness" of his premise just doesn't exist; the possibility of the statement being fact is buried under quite a bit of text and requires interpretation. As I'm realizing, they're just not understanding that their argument assumes many unsubstantiated premises, and ignores some more plausible premises (and the conclusions that can be drawn from them). I'd get into details, if it weren't religious in nature, so excuse any butchery in my attempt to describe this in purely logical terms.

 

Too many big words for a knuckle dragging, booger eating, mouth breather like me. head too ouchie! lol