Ethos is when an argument is constructed based on the ethics or credibility of the person making the argument. Ethos is in contrast to pathos (appealing to emotions) and logos (appealing to logic or reason).
Ethos is the appeal focused on the writer. It refers to the character of the writer, including her credibility and trustworthiness. The reader must be convinced that the author is an authority and merits attention. In scientific research, the author must establish her credibility as a rigorous and expert researcher.
Ethos is about establishing your authority to speak on the subject, logos is your logical argument for your point and pathos is your attempt to sway an audience emotionally. Leith has a great example for summarizing what the three look like.
the fundamental character or spirit of a culture; the underlying sentiment that informs the beliefs, customs, or practices of a group or society; dominant assumptions of a people or period: In the Greek ethos the individual was highly valued. the character or disposition of a community, group, person, etc.
Logos appeals to the audience’s reason, building up logical arguments. Ethos appeals to the speaker’s status or authority, making the audience more likely to trust them. Pathos appeals to the emotions, trying to make the audience feel angry or sympathetic, for example.
Logos is the appeal towards logical reason, thus the speaker wants to present an argument that appears to be sound to the audience. Aristotle stated that an argument should prove something or at least it should appear to prove something. Aristotle distinguished between scientific and rhetorical proof.
EVIDENCE: Ethos aligns most closely with Social evidence. Examples include quotes from experts, endorsements from authority figures, or support from groups with high credibility regarding an issue.