“No True Scotsman” Fallacy _ the arguer defines a term in a biased way in order to protect his position from rebuttals.
“You can believe what you want about Creation but no real scientist would agree with you. You don’t have any degrees!”
The “No True Scotsman” fallacy is actually made up of several fallacies. It’s a blend of equivocation and begging the question (possibly with an epithet) with a twist of faulty appeal to authority thrown in for garnish.
The redefinition of terms coupled with a derogatory remark makes this fallacy a popular weapon in heated debates when the two sides run out of intelligent things to say.
In our example above, suppose we brought in a well-known and highly credentialed expert to weigh the evidence. If he agreed with the Creationist, he could be dismissed as not being a real scientist. If he disagreed, one could use his notoriety as a faulty appeal to authority.
Truth exists in what is, not who says it. Reality is a powerful voice and it always gets the last word.