A form of Truth Bias where one invokes "truth" as a self-justifying warrant for their position, treating their claims as simply what's true and therefore beyond challenge. The fallacy lies in using the concept of truth to immunize one's views from examination—"I'm just telling the truth" becomes a way of saying "I don't need to argue, because what I say is simply reality." This fallacy shuts down inquiry rather than advancing it, positioning the speaker as the conduit of truth and all opponents as either deceived or deceivers. It's argument by assertion of virtue, not by evidence or reason.
Example: "She responded to every question with 'I'm just telling the truth'—as if saying it made it so. Argumentum Ad Veritatem: using the word 'truth' to avoid having to demonstrate it."
Fogey/fogy /fougi/ sl. (early 18C+, orig. Scot) old-fashioned, stuck-in-the mud.
Person with old fashioned ideas which he is unwilling to change: Come to the disco and stop being such an old fogey!
You think me an old fogeyand an old tory, his thoughtful voice said. I saw three generations since O’Connel’s time. I remember the famine. Do you know that the orange lodges agitated for repeal of the union twenty years before O’Connel did or before the prelates of your communion denounced him as a demagogue? You fenians forget some things. (James Joyce, Ulysses. Penguin Books,1992. p. 38)