logos (rhetoric)

Glossary of Grammatical and Rhetorical Terms

Logic meets inspiration
"The enthymeme and the example are the forms that reasoning takes in rhetoric" (Corbett and Connors, Classical Rhetoric for the Modern Student, 1999). (kimberrywood/Getty Images)

In classical rhetoric, logos is the means of persuasion by demonstration of logical proof, real or apparent. Plural: logoi. Also called rhetorical argument, logical proof, and rational appeal.

Logos is one of the three kinds of artistic proof in Aristotle's rhetorical theory.

"Logos has many meanings," notes George A. Kennedy. "[I]t is anything that is 'said,' but that can be a word, a sentence, part of a speech or of a written work, or a whole speech.

It connotes the content rather than the style (which would be lexis) and often implies logical reasoning. Thus it can also mean 'argument' and 'reason' . . .. Unlike 'rhetoric,' with its sometimes negative connotations, logos [in the classical era] was consistently regarded as a positive factor in human life" (A New History of Classical Rhetoric, 1994). 

See Examples and Observation below.


From the Greek, "speech, word, reason"

Examples and Observations

  • "Aristotle's third element of proof [after ethos and pathos] was logos or logical proof. . . . Like Plato, his teacher, Aristotle would have preferred that speakers use correct reasoning, but Aristotle's approach to life was more pragmatic than Plato's, and he wisely observed that skilled speakers could persuade by appealing to proofs that seemed true."
  • Logos and the Sophists
    "Virtually every person considered a Sophist by posterity was concerned with instruction in logos. According to most accounts, the teaching of the skills of public argument was the key to the Sophists' financial success, and a good part of their condemnation by Plato..."
  • Logos in Plato's Phaedrus
    "Retrieving a more sympathetic Plato includes retrieving two essential Platonic notions. One is the very broad notion of logos that is at work in Plato and the sophists, according to which 'logos' means speech, statement, reason, language, explanation, argument, and even the intelligibility of the world itself. Another is the notion, found in Plato's Phaedrus, that logos has its own special power, psychagogia, leading the soul, and that rhetoric is an attempt to be an art or discipline of this power."
  • Logos in Aristotle's Rhetoric
    - "Aristotle's great innovation in the Rhetoric is the discovery that argument is the center of the art of persuasion. If there are three sources of proof, logos, ethos, and pathos, then logos is found in two radically different guises in the Rhetoric. In I.4-14, logos is found in enthymemes, the body of proof; form and function are inseparable; In II.18-26 reasoning has force of its own. I.4-14 is hard for modern readers because it treats persuasion as logical, rather than emotional or ethical, but it is not in any easily recognizable sense formal."
  • Logos vs. Mythos
    "The logos of sixth- and fifth-century [BC] thinkers is best understood as a rationalistic rival to traditional mythos--the religious worldview preserved in epic poetry. . . . The poetry of the time performed the functions now assigned to a variety of educational practices: religious instruction, moral training, history texts, and reference manuals (Havelock 1983, 80). . . . Because the vast majority of the population did not read regularly, poetry was preserved communication that served as Greek culture's preserved memory."
  • Proof Questions
    Logical proofs
     (SICDADS) are convincing because they are real and drawn from experience. Answer all of the proof questions that apply to your issue.
    • Signs: What signs show that this might be true?
    • Induction: What examples can I use? What conclusion can I draw from the examples? Can my readers make the "inductive leap" from the examples to an acceptance of the conclusion?
    • Cause: What is the main cause of the controversy? What are the effects?
    • Deduction: What conclusions will I draw? What general principles, warrants, and examples are they based on?
    • Analogies: What comparisons can I make? Can I show that what happened in the past might happen again or that what happened in one case might happen in another?
    • Definition: What do I need to define?
    • Statistics: What statistics can I use? How should I present them 




    Halford Ryan, Classical Communication for the Contemporary Communicator. Mayfield, 1992

    Edward Schiappa, Protagoras, and Logos: A Study in Greek Philosophy and Rhetoric, 2nd ed. University of South Carolina Press, 2003

    James Crosswhite, Deep Rhetoric: Philosophy, Reason, Violence, Justice, Wisdom. The University of Chicago Press, 2013

    Eugene Garver, Aristotle's Rhetoric: An Art of Character. The University of Chicago Press, 1994

    Edward Schiappa, The Beginnings of Rhetorical Theory in Classical Greece. Yale University Press, 1999

    N. Wood, Perspectives on Argument. Pearson, 2004