Syllogisms and Visual Rhetoric

1. Syllogisms and Visual Rhetoric Danna Prather

2. Syllogistic form puts an argument into three statements in order to illustrate the data, claim, and warrant, but uses special terms to designate these.

3. Syllogistic Form- Categorical Syllogisms • All history professors are poor lecturers (Major premise) • Dr. Fred is a history professor (Minor premise) • Dr. Fred is boring (Conclusion) • Major term: history professors • Middle term: poor lecturers • Minor term: Dr. Fred

4. The Categorical Syllogism - Tests 1. The middle term must be used in a universal sense in one of the premises. • All people breath • Rachel is a person • Rachel breathes • This example passes - why?

5. The Categorical Syllogism – Tests 2. If a term is universal in the conclusion, it must be universal in the premises. • All people with cars must take driving lessons • Many college graduates have cars • All college graduates should take driving lessons • This example fails – why?

6. The Categorical Syllogism - Tests • 3. At least one of the premises must be an affirmative statement. • No Republicans vote Democrat • Matt is not a Republican • Matt votes democrat • Fails – why?

7. The Categorical Syllogism - Tests • 3. If one premise is negative, the conclusion must be negative. • No North Texans believe in the hollow earth • Julie is a North Texan • Julie doesn’t believe in the hollow earth • Passes – why?

8. Syllogistic Form – Hypothetical Syllogism • Major premise is concerned with an uncertain condition • If a universal health care system is financed through income tax, it will win approval • The proposed health care system is financed through an income tax • It will win approval

9. The Hypothetical Syllogism- Tests • 1. If the minor premise affirms the antecedent (the conditional clause), the conclusion must affirm the consequent. • If you run with scissors, you will cut yourself • You will run with scissors • You won’t cut yourself • Fails – why?

10. The Hypothetical Syllogism-Tests • 2. If the minor premise denies the consequent, the conclusion must deny the antecedent. • When I eat too much, I get sick • I didn’t get sick • I didn’t eat too much • Passes – why?

11. The Disjunctive Syllogism • The Major premise presents alternatives, usually indicated by an “either–or” or “neither—nor” • Either you will go to class this afternoon or you will fail • You didn’t go to class • You are going to fail

12. The Disjunctive Syllogism - Tests • 1. If the Minor premise affirms (or denies) one of the alternatives, the conclusion must deny (or affirm) the other alternative • Either I have to get a part time job or I will have to quit school • I didn’t get a part-time job • I will have to quit school • Passes – why?

13. The Disjunctive Syllogism – Tests • 2. The alternatives presented in the first premise must be mutually exclusive. • Either we take our time or we will be unfair • We will take our time • We will not be unfair • Fails – why? • Either we will take our time or we will be quick • We took our time • We were not quick • Passes – why?

14. The Disjunctive Syllogism - Tests • 3. The major premise must include all of the possible alternatives. • Jay does poor work so he must either be stupid or lazy • Jay is not stupid • He must be lazy • Fails – why?

15. Enthymemes and Visual Rhetoric • Enthymeme - as we learned yesterday, an enthymeme is a rhetorical syllogism • An argument where part is implied. Invites audience participation. • “Santa Claus is coming” • Data for the unstated claim, You better be good • “Everybody graduates sometime” • Data for the unstated claim you will graduate also

21. Importance of Cultural History for Visuals

25. Now and Then