The Ethical Criticism of Reasoning
“There is nothing controversial in saying that a reasoner’s character is an entrance requirement for an argument to be worth listening to.[…]But many would argue that an entrance requirement is all it is. There is all the difference in the world between having a reason to listen to someone and having a reason to accept what someone says. “Arguments are to be accepted by authority of the speaker’s reasons, not by reason of the speaker’s authority” (MacCormick 1982, 274). That is, people, have ethical qualities; arguments have logical qualities.”
Garver, Eugene. "The Ethical Criticism of Reasoning." Philosophy & Rhetoric 31, no. 2 (1998): 107-130. http://www.jstor.org/stable/40237990.