Introduction

It is Friday and Mr. Smith’s students are hoping he will cut class short. Cody shouts, “Mr. Smith, let us go home early!” “No way,” Mr. Smith says. Then Zara says, “Mr. Smith, it is almost 100 degrees Fahrenheit outside. Additionally, the air conditioner in our classroom is broken, so it will become dangerously hot in here by the end of the day. If we stay for the whole class, some students might even faint. Thus, it makes the most sense for us to leave class early.” Mr. Smith responds, “That does make the most sense, Zara. Now that you’ve convinced me, I will end the class two hours early to ensure everyone’s safety.”

Explanation

Zara’s rhetoric was successful, but Cody’s was not. While Cody simply demanded the outcome he wanted, Zara convinced Mr. Smith by persuading him with factual language. She started by using the temperature as a data point to provide a basis for her claims. She then listed the obstacles in place for progressing safely with a full class period and explained what could happen if Mr. Smith did not cut class short. She finished by indicating she had reached her conclusion with the word “thus.” As a result of Zara’s use of facts, data, signposting words, and a logically structured argument, Mr. Smith agreed with her and allowed the class to leave early. The strategies Zara used form an appeal to logos

Definition of Logos

Logos is the rhetorical appeal to logic or reason. It refers to the use of reason as the means of persuasion in an argument.

The History

In the third century B.C., the Greek philosopher Aristotle discussed logos as one of the three “modes of persuasion,” which are also known as “the three rhetorical appeals.” The word logos comes directly from Greek, where it could mean “word,” “speech,” “discourse,” or “reason.” 

Using It

An appeal to logos refers to the audience’s need or desire to hear reasonable-sounding arguments in order to be persuaded, rather than reason or logic in itself. Thus, while a rhetorician may appeal to logos by using certain facts and figures, those pieces of evidence may not actually support their claim. For example, the speaker may frame their numerical evidence in a misleading way, or they may commit a logical fallacy in their argument. Nonetheless, they have successfully appealed to logos if those facts and figures have influenced their audience. Hence, a successful appeal is largely audience dependent.

As a rhetorician, you must be aware of your audience and the types of evidence that will persuade them. The type of evidence most commonly associated with logos is numerical data. However, a rhetorician can also appeal to logos in the form of non-research based facts and arguments, including anecdotal evidence. In either case, the evidence must logically lead to the speaker’s claim, or at least appear to do so.

To be a good civic leader, you should use evidence correctly and accurately when appealing to logos in your speech or writing. You can do this by citing statistics, signs, and examples that support your claim and by using signpost words or phrases to signal your movements through an argument. Some examples include words and phrases such as first, next, specifically, alternatively, consequently, as a result, and in conclusion. These signposts can keep you from missing important steps in your argument and help the audience follow the reasoning. Ultimately, an honest attempt to show the logic of something with facts to back it up is a useful approach to making successful appeals to logos.

    Learn More

    1. “Appeals to Logos.” UMRhetLab, 2009, https://courses.lumenlearning.com/olemiss-writing100/chapter/appeals-to-logos/.
    2. “Logos” Literary Devices. 1 May 2017. Web. 5 Dec. 2017. http:/www.literarydevices.com/logos/.
    3. Scopa, Sally. “Logos.” LitCharts. LitCharts LLC, 5 May 2017. https://www.litcharts.com/literary-devices-and-terms/logos
    4. Ting, Su H. “Ethos, Logos and Pathos in University Students’ Informal Requests.” Gema Online Journal of Language Studies, vol. 18, no. 1, 2018. http://dx.doi.org.exlibris.colgate.edu:2048/10.17576/gema-2018-1801-14.
    5. Varpio, L. “Using rhetorical appeals to credibility, logic, and emotions to increase your persuasiveness.” Perspectives on Medical Education, vol. 7, May 2018, pp. 207–210. https://doi.org/10.1007/s40037-018-0420-2.

    Think Further

    1. How do words and numerical evidence pose varying challenges when appealing to logos?
    2. In what situations would it be useful to appeal to logos?
    3. Why does it matter whether an appeal to logos utilizes sound reasoning or fallacious reasoning?

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