evidence (argument)

Glossary of Grammatical and Rhetorical Terms

Inspector Poirot
"Real evidence," says Inspector Poirot, "has to be examined--sifted" (The Mysterious Affair at Styles by Agatha Christie, 1920). (RetroAtelier/Getty Images)


In argumentation, evidence refers to facts, documentation, or testimony used to strengthen a claim, support an argument, or reach a conclusion.

Evidence isn't the same as proof. "Whereas evidence allows for professional judgment, proof is absolute and incontestable" (Denis Hayes, Learning and Teaching in Primary Schools, 2009).

See Examples and Observations below. Also see:

Evidence in Arguments:

From the Latin, "obvious"

Examples and Observations

  • "Without evidence to support them, any statements you make in your writing have little or no value; they're simply opinions, and ten people may have ten different opinions none of which is more valid than the others unless there is clear and potent evidence to support it."
    (Neil Murray, Writing Essays in English Language and Linguistics. Cambridge University Press, 2012)
  • "The fact that an opinion has been widely held is no evidence whatever that it is not utterly absurd; indeed in view of the silliness of the majority of mankind, a widely spread belief is more likely to be foolish than sensible.”
    (Bertrand Russell, Marriage and Morals, 1929)
  • "When conducting empirical research, the researcher's primary responsibility is to provide evidence to support his or her claim about the relationship between the variables described in the research hypothesis. . . . [T]he researcher must collect data that will convince us of the accuracy of his or her predictions."
    (Bart L. Weathington et al., Research Methods for the Behavioral and Social Sciences. John Wiley, 2010)
  • Making Connections
    "A common assumption about evidence is that is is 'the stuff that proves I'm right.' Although this way of thinking about evidence is not wrong, it is much too limited. Corroboration (proving the validity of a claim) is one of the functions of evidence, but not the only one. . . .

    "Writing well means sharing your thought process with your readers, telling them why you believe the evidence means what you say it does. . . .

    "Writers who think that evidence speaks for itself often do very little with their evidence except put it next to their claims: 'The party was terrible: there was no alcohol'--or, alternatively, 'The party was great: there was no alcohol.' Just juxtaposing the evidence with the claim leaves out the thinking that connects them, thereby implying that the logic of the connection is obvious. But even for readers prone to agreeing with a given claim, simply pointing to the evidence is not enough."
    (David Rosenwasser and Jill Stephen, Writing Analytically, 5th ed. Wadsworth, 2009)
  • Qualitative and Quantitative Evidence
    "The mere presence of information does not constitute evidence; the informative statements must be accepted as evidence by an audience and believed by it to be relevant to the claim at issue. Evidence can be generally classified as qualitative and quantitative. The former emphasizes explanation and description, appearing continuous rather than discrete, while the latter offers measurement and prediction. Both kinds of information require interpretation, for at no time do the facts speak for themselves."
    (Julie M. Farrar, "Evidence." Encyclopedia of Rhetoric and Composition, ed. by Theresa Enos. Routledge, 2006)
  • Opening the Door
    "The more far-reaching effect of introducing evidence [in a trial] is to pave the way for other parties to introduce evidence, question witnesses, and offer argument on the subject in attempts to rebut or confine the initial evidence. In the customary phrase, the party who offers evidence on a point is said to have 'opened the door,' meaning that the other side may now make countermoves to answer or rebut the initial evidence, 'fighting fire with fire.'"
    (Christopher B. Mueller and Laird C. Kirkpatrick, Evidence: Practice Under the Rules. Aspen Publishers, 1999)
  • Dubious Evidence
    - "[I]s there any research to show that a physical exam--in a healthy person--is of any benefit? Despite a long and storied tradition, a physical exam is more a habit than a clinically proven method of picking up disease in asymptomatic people. There is scant evidence to suggest that routinely listening to every healthy person’s lungs, or pressing on every normal person’s liver, will find a disease that wasn’t suggested by the patient’s history. For a healthy person, an 'abnormal finding' on a physical exam is more likely to be a false positive than a real sign of illness."
    (Danielle Ofri, "Not on the Doctor’s Checklist, but Touch Matters." The New York Times, Aug. 2, 2010)

    - "America must not ignore the threat gathering against us. Facing clear evidence of peril, we cannot wait for the final proof, the smoking gun that could come in the form of a mushroom cloud."
    (President George W. Bush, in justifying the invasion of Iraq in 2003)

    - "We have it. The smoking gun. The evidence. The potential weapon of mass destruction we have been looking for as our pretext of invading Iraq. There's just one problem: it's in North Korea."
    (Jon Stewart, The Daily Show, 2005)

  • The Lighter Side of Evidence
    "Tell people there's an invisible man in the sky who created the universe, and the vast majority will believe you. Tell them the paint is wet, and they have to touch it to be sure.”
    (George Carlin)

Pronunciation: EV-i-dens