Logos is the persuasive appeal to reason and logic. Aristotle identified it as one of the three primary modes of rhetoric, alongside ethos and pathos.

An argument that relies on logos presents evidence, draws inferences, and structures claims so that they follow from premises. Statistics, examples, causal analysis, and formal deduction all fall under its scope. Clear organization and precise language support the logical appeal. Audiences accept a logos-driven argument when they find the evidence sufficient and the reasoning sound.

Logos alone is rarely enough; credibility and emotional resonance usually work alongside it. Yet without a logical backbone, persuasion collapses into manipulation or mere assertion. In academic, legal, and technical contexts, logos is expected to carry most of the weight. Writers strengthen logos by anticipating counterarguments and by making the steps of their reasoning visible.

The part of persuasion that addresses the audience’s capacity to reason is logos.