Charles Leslie Stevenson (June 27, 1908 – March 14, 1979) was an American analytic philosopher best known for his work in ethics[2] and aesthetics.

He was an instructor at Yale University from 1939 to 1944, spending some of that time teaching mathematics to wartime naval recruits.

Stevenson's work has been seen both as an elaboration upon A. J. Ayer's views and as a representation of one of "two broad types of ethical emotivism.

[8] Where Ayer spoke of values, or fundamental psychological inclinations, Stevenson speaks of attitudes, and where Ayer spoke of disagreement of fact, or rational disputes over the application of certain values to a particular case, Stevenson speaks of differences in belief; the concepts are the same.

Under his first pattern of analysis, an ethical statement has two parts: a declaration of the speaker's attitude and an imperative to mirror it, so "'This is good' means I approve of this; do so as well.

Imperatives cannot be proved, but they can still be supported so that the listener understands that they are not wholly arbitrary: If told to close the door, one may ask "Why?"

[15] Logical methods involve efforts to show inconsistencies between a person's fundamental attitudes and their particular moral beliefs.

Such a revelation would likely change the observer's belief about Edward, and even if it did not, the attempt to reveal such facts would count as a rational psychological form of moral argumentation.

Stevenson called the primary such method "'persuasive,' in a somewhat broadened sense", and wrote: [Persuasion] depends on the sheer, direct emotional impact of words—on emotive meaning, rhetorical cadence, apt metaphor, stentorian, stimulating, or pleading tones of voice, dramatic gestures, care in establishing rapport with the hearer or audience, and so on.

… A redirection of the hearer's attitudes is sought not by the mediating step of altering his beliefs, but by exhortation, whether obvious or subtle, crude or refined.