Public Speaking Persuasion Week 12 Argument Building an

Public Speaking Persuasion: Week 12 - Argument

Building an Argument An argument: a set of two or more propositions related to each other in such a way that all but one of them (the premises) are supposed to provide support for the remaining one (the conclusion).

Something to Remember: A claim or assertion + reasons does not automatically = a good argument.

Components of Argument Logic Proposition Premise Inference Conclusion

Definitions Logic The study of the distinction between correct and incorrect reasoning. Examples of Poor Logic: “I bought a large pizza yesterday because I found $15 on the street. I am going to buy another larger pizza today, because I’m sure I’ll find another $15 on the street. ” “Yes the roads are really torn up due to construction, but I’d rather use space in the truck to bring my massive stereo speakers with me to college rather than a spare tire. ”

Definitions, Logic cont. Examples of sound logic: “I saw with my own eyes that her texting app works fine. I also overheard her tell Jill she’s a little pissed at me. So, I assume she got my texts, but is waiting to cool down before answering me (if she even chooses to). ” “Yes, I get annoyed sometimes with people who are without homes, especially when they come up to me on the street. However, I also know that when I’ve gotten two hours less sleep and no coffee, I feel out of my mind. I guess I might seem crazy too if I slept outside for two weeks straight, never ate, never showered properly, and had no privacy. I guess the situation can have an effect on you. ”

Definitions Proposition or claim: A declarative statement that can either be true or false. Examples: “Eating Reese’s Pieces everyday increases your probability for diabetes. ” “Orange juice is the worst tasting fruit juice available. ” “Today‘s pop music is fine; pop music has ALWAYS been formulaic and soulless. ” “The higher a woman’s level of education, the later in life she marries and has children. ”

Definitions: Premise A statement who’s truth is used to infer that of others. In our previous example (people without homes), our premise was the following: “I also know that when I’ve gotten two hours less sleep and no coffee, I feel out of my mind. ” Our premise is that even people with homes, when they miss a few very basic everyday elements of their lives, act “crazy” “anger” or otherwise “not normal”.

Definitions, Inference: A. the relationship that holds between the premises and the conclusion of a logical argument. B. the process of drawing a conclusion from premises that support it deductively or inductively.

Inference Continued Claim: All lions are cats. Premise: Some cats live outdoors. Conclusion: Some lions live outdoors. Claim: Seventeen of the eighteen warmest years in the 136 year record have all occurred since 2001. Premise: Global carbon emissions rose from 500 mmt. to 11, 000 mmt. From 1900 to 2014. Conclusion: We need to significantly reduce our carbon footprint or else we will destroy the earth.

Deductive Arguments Deductive arguments: arguments that lead to necessary conclusions when their reasons are true Premises: what we call reasons in a deductive argument.

Deductive Arguments Flow of a deductive argument: “major premise” (general principles) then “minor premise” (more specific observation) then a conclusion that applies the major premise to a particular case. Think of it as “Top down”

Inductive Arguments Inductive arguments: arguments whose reasons lead to probable conclusions Probable conclusion: a conclusion that can be shown to be more or less likely, but not necessary. Typically moves from specific observations to a general conclusion

Inductive Arguments Think of them as “bottom up” Inductive arguments involve an inductive leap or a reasoning process in which the conclusion of an inductive argument moves beyond its stated evidence.

Definition, Conclusion A proposition whose truth has been inferred on the basis of other propositions assembled with it in a logical argument.