to which the best response is to give up and walk away, if the person is arguing from a fundamentally different set of precepts FGA or no there's no point.
that same person could also argue that their position is true because Kermit the frog has decreed as such.
The insidious subtly of FGA's is that in a rational argument between sensible people an FGA can be used without anyone saying things which are obviously untrue or obviously stupid/insane. It's simply that an FGA is so broad that either side could use the FGA and have it feel like it supports their position.
Follow-up to: Knowing About Biases Can Hurt People
See also: Fully General Counterargument (LW Wiki)
With the caveat that the arguer doesn't need to be aware that this is the case. But if (s)he is not aware of that, this seems like the other biases we are prone to. The question is: Is there a tendency or risk to accidentally form FGCAs? Do we fall easily into this mind-trap?
This post tries to (non-exhaustively) list some FGCAs as well as possible countermeasures.
The List
Here is a list of my own making:
Do you now some more? Into what clusters do these FGCAs fall?
Self-sealing Belief
Why do we use FGCAs? One reason may be when we are arguing from within a self-sealing belief:
Preventive Action
What are known ways to avoid FGCAs?
One specific method against this mind trap is being humbly gullible.
Another is to practice Steelmanning as long as you avoid the dangers of steelmanning. Especially applicable is Steelmanning Inefficiency.
More general advice can of course be found in the Twelve Virtues of Rationality. See also the concise and improved versions.