A History of Philosophy: Volume II: Medieval Philosophy, (Continuum: 2003) p. 53
Again, everyone who doubts knows that he is doubting, so that he is certain of this truth at least, namely the fact that he doubts. Thus every one who doubts whether there is such a thing as truth, knows at least one truth, so that his very capacity to doubt should convince him that there is such a thing as truth.
Reason, if there is such a thing, can serve as a court of appeal not only against the received opinions and habits of our community but also against the peculiarities of our personal perspective. It is something each individual can find within himself, but at the same time it has universal authority. Reason provides, mysteriously, a way of distancing oneself from common opinion and received practices that is not a mere elevation of individuality… not a determination to express one’s idiosyncratic self rather than go along with everyone else. Whoever appeals to reason purports to discover a source of authority within himself that is not merely personal or societal, but universal… and that should also persuade others who are willing to listen to it. ~ Thomas Nagel, The Last Word
The Rodeo Clown Fallacy falters into illogic not in virtue of being a false target (straw man, red herring), but by being an ever changing and ever elusive target. That is, it evades logic. Just as the horns of an argument are about to make their point, some guy in a clown suit yells, “Yeah, but what about…” This clown is certainly a legitimate target in his own right, but the problem is that there will forever be another rodeo clown ready to distract with a giggly, “Yeah, but what about…,” so no bad ideas ever get gored. It turns out that something similar to this device has been “canonized” as “Shifting Ground”. “The fallacy is made when a debater being dislodged from one position, calmly takes another, and then another. For example, a student arguing in favor of the incorporations of labor unions argued first that incorporation would benefit the unions themselves; being driven from this stand by his opponent, he argued that incorporation would benefit the employers’ associations; finally, being compelled to yield on this also, he triumphantly closed the debate by maintaining that incorporation of labor unions would benefit the general public.” (U. of Wisconsin Dept. of Debating and Discussion, The Principles of Effective Debating, 1912, p. 34.)