[arbitrarywords]

Well the impression I get is the idea of a "cultural" muslim is contested from both within and without the muslim community so I don't think it's quite that clear cut. Who gets to own the labels seems to always be a political battle. You could argue that it is only "reasonable" to use the label for those who hold the beliefs.

[tunesmith]

I'm not really sure if there's a term for the problem with this, but "moral hazard" may apply. If a determination is made to exclude all "cultural muslims" from the definition of muslim, then that determination is probably made by someone who is not a "cultural muslim", and the effects might really suck for the cultural muslims.

[MarkTee]

No true Scotsman

How do you decide who owns the "right" beliefs? By that logic, who can we consider to be a Christian?

[lotharbot]

"No true Scotsman" is only a fallacy when one uses irrelevant criteria to exclude people from a group.

It's not NtS to point out that James "Scotty" Doohan wasn't Scottish (he was a Canadian of Irish descent.) Nor is it NtS to point out that certain people don't hold various relevant defining characteristics and therefore to claim that they don't count as being in a particular category. Of course, that exclusion is contextual -- it can apply to a particular use of a label without applying to all uses of it.

Note that I disagree with Sam Harris overall. His claim is that the only way Muslims can be reasonably said to exist is his definition; I would argue that one way Muslims can be said to exist is his definition. I would further argue that some people who use other definitions of Islam have irrational/unjustified/disproportionate fear, and can therefore be said to be Islamophobic.