Formulating a logical argument using Inductive and Deductive Reasoning FOCUS ON LOGOS Formulating a logical argument using Inductive and Deductive Reasoning

Rhetorical Triangle

Appeals to Logic (logos) Theoretical, abstract  language Denotative meanings/reasons Literal and historical analogies Definitions Factual data and statistics Quotations Citations from experts and authorities Informed opinions

ARGUMENT = CLAIM + SUPPORT FOR CLAIM Arguments use either DEDUCTIVE or INDUCTIVE reasoning.

Deductive Arguments argument from the general to the particular. leads to certain conclusions. arguments are valid or invalid.

Examples of Deductive Reasoning All men are mortal (major premise) Socrates was a man (minor premise) Therefore Socrates was mortal. (conclusion) If it rains, the sidewalks become wet It is raining Therefore the sidewalks are wet.

…Deductive reasoning contd. All women are brilliant. (major premise) I am a woman. (minor premise) Therefore, I am brilliant. (conclusion) Everyone who has been exposed to the Ebola virus has died. John Q. has been exposed to the Ebola virus. John Q. will die.

Inductive Arguments argument from particular observations to general conclusions. leads to probable conclusions, not necessary ones. arguments can be better or worse depending on degree of probability.

Examples of Inductive Reasoning Socrates was Greek’ Most Greeks eat fish Socrates ate fish. Eddie has failed to follow through with his education, in his relationships with women, and with the jobs that he has previously held, therefore he will probably not follow through on this assignment.

Inductive Arguments contd. Many people who smoke seem to get cancer.  Thus, if you want to avoid getting cancer, don't smoke.

Logical Fallacies (p. 631 in RCWW) Example: Why is counterfeiting illegal? I’ll tell you why. It is because it is against the law! We sin, because we are sinners.

LOGICAL REASONING EXERCISE: Penguins make great pets. Milk should be banned. People really don’t need skin. The new pizza diet is wonderful. Tabloids should replace texts. Humans should always go barefoot. Hot-air balloons make great commute vehicles. Children should be able to vote.