What's the worst argument you can think of?

One of my favorites is from a Theodore Sturgeon science fiction story in which it's claimed that faster than light communication must be possible because even though stars are light years apart, a person can look from one to another in a moment.

I don't know about you, but bad logic makes my stomach hurt, especially on first exposure.

This seems rather odd-- what sort of physical connection might that be?

Also, I'm not sure how common the experience is, though a philosophy professor did confirm it for himself and (by observation) his classes. He mentioned one of the Socratic dialogues (sorry, I can't remember which one) which is a compendium of bad arguments and which seemed to have that effect on his classes.

So, how did you feel when you read that bit of sf hand-waving? If your stomach hurt, what sort of stomach pain was it? Like nausea? Like being hit? Something else? If you had some other sensory reaction, can you describe it?

For me, the sensation is some sort of internal twinge which isn't like nausea.

Anyway, both for examination and for the fun of it, please supply more bad arguments.

I think there are sensory correlates for what is perceived to be good logic (unfortunately, they don't tell you whether an argument is really sound)-- kinesthesia which has to do with solidity, certainty, and at least in my case, a feeling that all the corners are pinned down.

Addendum: It looks as though I was generalizing from one example. If you have a fast reaction to bad arguments and it isn't kinesthetic, what is it?