Classical Rhetoric and Aristotle

Aristotle defined rhetoric as "an ability, in each [particular] case, to see the available means of persuasion.  Some means are external to the argumentation, i.e. blackmail or threats. However, others means of persuasion are internal to an argument: logos, pathos, and ethos.

Logos

The main concern in an argumentation-persuasion presentation should be with the logos, or soundness, of your argument. This includes the facts, statistics, examples, and authoritative statements you gather to support your viewpoint. This supporting evidence must be unified, specific, sufficient, accurate, and representative. Imagine, for instance, you want to convince people that a popular charity misappropriates the money it receives from the public. Your readers, inclined to believe in the good works of the charity, will probably dismiss evidence that enhances your position unless your reasoning, or Logos, is very sound.

Pathos

Sensitivity to the pathos, or the emotional power of language, is another key consideration for creators of argumentation-persuasion presentations. Pathos appeals to a viewpoint or course of action. The pathos of a piece derives partly from the communicators choice of language. Connotative language, for example, are words with strong emotional overtones and have the ability to move the audience to accept a point of view and may even spur them to act. Adolf Hitler, during World War II, was very effective with the use of propaganda filled with elements of pathos in order to convince the country and rally support for his cause.

Ethos

Finally, whenever presenting any argument or persuasion, the establishment of ethos, or credibility and reliability is very important. The audience cannot be expected to accept or act on your viewpoint unless you convince them that you know what you're talking about and that you're worth listening to. You will come across as knowledgeable and trustworthy if you present a logical, reasoned argument that takes opposing views into account. It is also important to make sure that the appeals to emotion are not excessive. Too much emotionalism tends to undercut credibility.

Overall

The delivery of any good argumentation-persuasion presentation involves an interplay of logos, pathos, and ethos. The exact balance among these factors is determined by the audience and purpose, that is, whether or not you want the audience simply to agree with your view or whether you also want them to take action. For the execution of this, the presentation should be tailored to the audience and its needs: how much the audience knows about the issue, how they feel about you and your position, what their values and attitudes are, and what motivates them should all be taken into account.

Information accessed at http://www.ou.edu/class/engl3143/group3/