In order to persuade their readers, writers must use three types of proofs or rhetorical appeals. They are logos, or logical appeal; pathos, or emotional appeal; and ethos, or ethical appeal, or appeal based on the character and credibility of the author. It is easy to notice that modern words “logical,” “pathetic,” and “ethical” are derived from those Greek words. In his work Rhetoric, Aristotle writes that the three appeals must be used together in every piece of persuasive discourse. An argument based on the appeal to logic, or emotions alone will not be an effective one.
Understanding how logos, pathos, and ethos should work together is very important for writers who use research. Often, research writing assignments are written in a way that seems to emphasize logical proofs over emotional or ethical ones. Such logical proofs in research papers typically consist of factual information, statistics, examples, and other similar evidence. According to this view, writers of academic papers need to be unbiased and objective, and using logical proofs will help them to be that way.
Because of this emphasis on logical proofs, you may be less familiar with the kinds of pathetic and ethical proofs available to you. Pathetic appeals, or appeals to emotions of the audience were considered by ancient rhetoricians as important as logical proofs. Yet, writers are sometimes not easily convinced to use pathetic appeals in their writing. As modern rhetoricians and authors of the influential book Classical Rhetoric for the Modern Student (1998), Edward P.J. Corbett and Robert Connors said, “People are rather sheepish about acknowledging that their opinions can be affected by their emotions” (86). According to Corbett, many of us think that there may be something wrong about using emotions in argument. But, I agree with Corbett and Connors, pathetic proofs are not only admissible in argument, but necessary (86-89). The most basic way of evoking appropriate emotional responses in your audience, according to Corbett, is the use of vivid descriptions (94).
Using ethical appeals, or appeals based on the character of the writer, involves establishing and maintaining your credibility in the eyes of your readers. In other words, when writing, think about how you are presenting yourself to your audience. Do you give your readers enough reasons to trust you and your argument, or do you give them reasons to doubt your authority and your credibility? Consider all the times when your decision about the merits of a given argument was affected by the person or people making the argument. For example, when watching television news, are you predisposed against certain cable networks and more inclined towards others because you trust them more?
So, how can a writer establish a credible persona for his or her audience? One way to do that is through external research. Conducting research and using it well in your writing help with you with the factual proofs (logos), but it also shows your readers that you, as the author, have done your homework and know what you are talking about. This knowledge, the sense of your authority that this creates among your readers, will help you be a more effective writer.
The logical, pathetic, and ethical appeals work in a dynamic combination with one another. It is sometimes hard to separate one kind of proof from another and the methods by which the writer achieved the desired rhetorical effect. If your research contains data which is likely to cause your readers to be emotional, it data can enhance the pathetic aspect of your argument. The key to using the three appeals, is to use them in combination with each other, and in moderation. It is impossible to construct a successful argument by relying too much on one or two appeals while neglecting the others.
Consider two recent examples of fairly ineffective use of the three appeals. In the beginning of April 2008, two candidates for the Democratic Party's presidential nomination, Senators Hillary Clinton and Barack Obama began airing campaign television ads in Pennsylvania ahead of their party's primary presidential election in that state. You can see both ads below.
Clinton's ad is called "Scranton" and it is very heavy of pathos, or emotional appeal. It invokes very warm childhood memories which, the ad's creators hoped, would show Senator Clinton's "softer side" thus persuading more people to vote for her. The purpose of the ad is to stir emotion, and it does it rather well. The problem with this approach is, however, that it does not tell voters much about the concrete steps and activities Senator Clinton would undertake if elected. The ad is rather thin on the logical appeal, and this, in turn, affects Clinton's ethos or credibility.
Barack Obama's ad is called "One Voice," and is calling on his supporters to "change the world."
While this is certainly a worthy cause, it is not clear from this ad how exactly Obama - still a senator at the time - intended to change the world once elected. The reason for this lack of clarity is the heavy emphasis on the pathetic appeal at the expense of logos. If you followed the presidential campaign of 2008, you would know that the call for change which is so clear in this ad was Obama's main slogan, a statement than became a large part of his ethos, or persona as a politician and as a rhetorician. This ad succeeds in highlighting that part of Obama's political persona once again while, probably intentionally, under-emphasizing logos.