Appeals: Ethos, Pathos, Logos
A General Summary of Aristotle's Appeals
All writing is a form of rhetoric: the writer, with or without intention, uses language as a means to persuade his or her audience to a point of view. The Greek philosopher Aristotle divided the means of persuasion, or appeals, into three categories - ethos, pathos, logos.
Ethos (Credibility), or ethical appeal, is when the author uses his or her words to establish credibility. We tend to believe people whom we respect. One of the central problems of argumentation is to project an impression to the reader that you are someone worth listening to. For example, if you are an expert of sorts and you demonstrate this in some way, then you are using an appeal to ethos as a strategy to persuade.
Another way to do this is when you reference an expert or use the words of others to make yourself as author into an authority on the subject of the paper. When you use signal phrases, such as “According to a research study completed by anthropologist Clifford Gertz,” this also is an appeal to ethos. In other words, you raise your credibility by demonstrating that you have done your research and found some good strong evidence to support your claims.
Pathos (Emotional) refers to persuasion by appealing to the reader's emotions. Emotional appeals, expressive language, telling stories, description, are all powerful tools in helping others experience what you or someone else has experienced. Language choice affects the audience's emotional response, and descriptive, graphic narrative can effectively be used to persuade an audience to your point of view. However, pathos without reason can lead a reader to think with his heart and not his head. At the college level, a primary concern is that you think critically about issues, using both your emotions and your reasoning.
Logos (Logical) means to persuade by the use of reasoning. This is Aristotle's favorite appeal. Inductive and deductive reasoning are recognized at the college level as perhaps the most 
substantive means of persuasion. And yet, reasoning is not always the most powerful. Giving reasons, nonetheless, is the heart of argumentation, and cannot be emphasized enough. A claim is made and reasons or support are provided. Often ethos, establishing credibility for a claim (for example, "According to Dr. James Gee,") and pathos, appeals to emotion (for example, "Not long ago, a young woman...") are used to support a particular claim. In other words, ethos and pathos are often an important part of building a strong logical argument. And yet when we think of logos, we think of statistics, research-based claims and logical arguments. For example: A recent study completed with college graduates reports, “The average income of Associate’s degree graduate is $37,000 per year and that the average income of Bachelor’s degree graduate is $47,000 per year” (Johnson 2).