REASONING & LOGIC What’s the purpose of knowing? Reasoning is the “most” important and difficult skill a persuasive speaker can acquire. It adds to your tools for critical thinking.

The Persuasive Speaker’s Responsibilities! 1.Be an Effective Speaker a. Support Ideas b. Use good evidence c. Use valid reasoning 2. Type of Evidence : True (Aristotle’s Inartistic~Factual/Empirical) a. Numbers b. Credible Testimony from experts 3. Use Reasoning: The process of thinking and drawing conclusions 4. Know how to apply the reasoning 5. Know how to apply the different types of logic/appeals: Pathos, Ethos, and Logos 6. Remember that one argument with one piece of evidence “does not” make a fully developed persuasive speech! 7. Several arguments make a valid and challenging presentation (use 3 or 4).

The Methods or Modes of Reasoning – Inductive and Deductive I.Reasoning by Association/Analogy (sometimes considered a form of Inductive Reasoning): When faced with some unknown, humans will apply what they do know in an effort to figure out what they don’t know in an effort to understand. *The vast majority of all human reasoning is by analogy.

Reasoning by Analogy – Characteristics 1.The test of reasoning by analogy is how reasonable or satisfying the conclusion seems to be. 2.Normally, it has no argumentative force, but it is used to illustrate and clarify more than to logically support an argument. 3.The perfect analogy doesn’t exist. 4.Always, you must supplement with more proof.

How does it work? Example Process:Example: Data are accumulated by observation,An alien is seen waving a tentacle at experience, and/or communication.An observer. An attempt is made to interpret an un-This is like human hand waving; hand familiar event by comparing it to familiarsignifies friendship. events. A conclusion is drawn by analogy.The alien is trying to be friendly.

Reasoning by Traditional Inductive Reasoning I. Definition – Reasoning by expectation or known as Parallel reasoning (X-mas lights). Arguing from specific instances to general statements. II. Characteristics A. When an observer becomes aware of a “pattern”, that pattern creates a logical set of expectations. B. It’s only as valid as the available data is correct. C. The test of reasoning by induction is how statistically “probable” the conclusion is.

How does it work? Example Process:Example: Data are accumulated by observation, A number of aliens are observed experience, and/or communication.waving their tentacles; all reports about aliens say that they wave their tentacles. An attempt is made to discover a patternOne thing which seems to hold true or regularity in the data.for all aliens is that they wave their tentacles. A generalized conclusion is drawn.All aliens wave their tentacles.

INDUCTIVE APPROACH on PAPER 1.Present Evidence first with the cited source stated (attribute). 2.Present arguments based on the evidence. 3.Explain how this leads to the overall conclusion and what you as the speaker want the audience to do or believe.

Reasoning by Sign – a special sort of inductive reasoning. 1. Definition: Draw conclusions about a given situation based on physical evidence. 2. Example: Sherlock Holmes used inductive reasoning to solve his cases. 3. Reasoning by sign can be persuasive. a. Used in legal/law court cases. b. Helps in deciding policy because it used inartistic evidence (concrete in nature).

Reasoning by the Case Study – Another form of Inductive Reasoning 1.Allows one to study a “typical” example in great detail (EX. intern for a company to see and compare how it works-law firms). 2.You then draw “general” conclusions from the study (EX. How many hours does the average lawyer work a day?) 3.It carries no faults as does reasoning by sign (circumstantial evidence) and analogy (dissimilar things are compared).

Reasoning by Deductive Reasoning I.Definition: Reasoning by logical necessity; reasoning that moves from generalizations, premises, to specific instance (Series, like on a X-mas tree.) A. Premises are the statements on which reasoning is based. B. Syllogism: two premises and a conclusion (all students go to school; you are a student; therefore, you go to school.

DEDUCTIVE APPROACH on PAPER 1.The speaker tell the audience what they want them to do or believe as their conclusion. 2.Next, they present their arguments that support this conclusion. 3.Finally, they present their evidence which supports the argument including the cited source (attribute).

How Does it Work? Example Process:Example: Data are accumulated by observation,All aliens wave their tentacles; Observation, experience, and/or com-an alien is going to be giving a Munication; this includes facts, judgments,lecture later today. Values, and generalizations. The data, including logical rules and general-If all members of a class exhibit some Ized data, are transformed into a thoughttrait, then each member of the class Problem to be solved.Will exhibit that same trait. What does this suggest about the alien lecturer?

Example continued - Process:Example: A conclusion is “calculated” based upon theThe alien lecturer will wave his or her Available data, the rules which govern theor its tentacle. Application of that data, and the nature of the Thought problem as it was set up. *It may therefore be concluded (deductively) that there is no such thing as absolute truth (at least no truth that can be demonstrated by human reason). **Therefore, it follows that there is no such thing as absolute proof. ***All evidence may be challenged as long as it is not stipulated evidence. 1. The 1 st Amendment says to allow for all types of expression. 2. Flag burning is a type of expression. 3. Therefore, flag burning should be allowed.