(also known as: no true Christian*)
Description: When a universal (“all”, “every”, etc.) claim is refuted, rather than conceding the point or meaningfully revising the claim, the claim is altered by going from universal to specific, and failing to give any objective criteria for the specificity.
All X are Y.
(it is clearly refuted that all X are not Y)
Then all true X are Y.
Example #1: In 2011, Christian broadcaster, Harold Camping, (once again) predicted the end of the world via Jesus, and managed to get many Christians to join his alarmist campaign. During this time, and especially after the Armageddon date had passed, many Christian groups publicly declared that Camping is not a “true Christian”. On a personal note, I think Camping was, and is, as much of a Christian than any other self-proclaimed Christian, and, religious/political/ethical beliefs aside, I admire him for having the cahunas to make a falsifiable claim about his religious beliefs.
John: Once you accept Jesus as your savior, you will never stray from the LORD, hallelujah!
Marvin: Then why are there so many X-Christians?
John: They were never true Christians.
Marvin: What’s a true Christian?
John: Those who have the Holy Spirit.
Explanation: This is a very common form of this fallacy that has many variations. Every time one Christian denounces another Christian for doing or saying something that they don’t approve of, usually by the phrase, “he is not really a true Christian”, this fallacy is committed.
The universal claim here is that no Christian (as defined as one who accepts Jesus as his or her savior) will ever (universal) stray from the LORD. Marvin points out how clearly this is counterfactual, as there are millions of former Christians. Instead of conceding or meaningfully revising the claim, the implication that no Christian will stray is changed to “no true Christian”, which is not meaningful because John’s definition of a “true Christian” apparently can only be demonstrated in the negative if a Christian leaves the faith. This results in the questionable cause fallacy as it is also an unfalsifiable claim. And of course, it commits the no true scotsman fallacy.
Exception: A revised claim going from universal to specific that does give an objective standard, would not be fallacious. If this were the case, a false claim would still have been made, but no fallacy would follow.