[QUOTE=CookingWithGas]
[Quote=BabaBooey]
“Yeah, I’m sure you’re the bastian of the abstinent community”, and he didn’t know what the shit I was talking about.
[/quote]
Now that we’ve settled the matter of the existence of the word, I don’t know what the shit you’re talking about either. 
Maybe we should move from the spelling on to the definition.
[/QUOTE]
Since a bastion is a reinforced strongpoint in a fortification, it is often used metaphorically to mean a person who provides the moral strength to allow others of the same philosophy to rally round them when the group is under (philosophical) attack. From that meaning, it is sometimes sloppily extended to mean simply a strong proponent of any philosophical position.