ethos

A type of persuasion based on the character and credibility of a speaker Ethos is the appeal to ethics and is a means of convincing someone of the character of the persuader.

Ex. Credentials

examples:
 * "As a doctor, I am qualified to tell you that this course of treatment will likely generate the best results."
 * "If his years as a Marine taught him anything, it’s that caution is the best policy in this sort of situation."
 * "He is a forensics and ballistics expert for the federal government – if anyone’s qualified to determine the murder weapon, it’s him."
 * "If you’re still unsure, please consider that my advanced degree and field work speak for themselves."
 * "Based on the dozens of archaeological expeditions I’ve made all over the world, I am confident that those potsherds are Mesopotamian in origin."