Ethos is the persuasive appeal that rests on the character, credibility, or authority of the speaker or writer. Aristotle listed it as one of the three primary modes of rhetoric, alongside pathos and logos.

An audience is more likely to accept a claim when it trusts the person making the claim. Ethos is established through demonstrated expertise, good will, shared values, and a reasonable tone. A physician speaking about public health, a survivor recounting experience, or a carefully footnoted scholar all draw on different forms of ethos. The appeal can be undermined by inconsistencies, arrogance, or evident self-interest.

In writing, ethos is built by the quality of the argument, the fairness with which opposing views are treated, and the precision of the language. In speech, delivery and reputation also matter. Ethical persuasion does not replace evidence, but it creates the conditions in which evidence can be heard.

The sense that the speaker is worth listening to is the work of ethos.