Critical Thinking Crash Course

1. Critical Thinking Crash Course Topic 1: Deductive versus Inductive Logic

2. Reasoning and Communicating in the American Academic Context • Reasoning Types • Deductive • Inductive • What They Mean • How We Use Them • When reading • When writing

3. Validity • To break down an argument, we have to know what makes it valid. There are three contexts that affect the accuracy and appropriateness of a reasoning structure. • Internal to the argument itself • Does it follow the process or steps necessary to that reasoning structure? • Its use within a field or context • Its use as part of the structure/structures of a text or work

4. The Types of Reasoning • For both deductive and inductive reasoning, there are four generally recognized (and recognizable) types: • Deductive=general to specific • Categorical (universal and non-universal) • Conditional • Conjunctive • Disjunctive • Inductive=specific to general • Causal • Sign • Analogy • Generalization Language for induction elements and evaluation methods based on John Lucaites’ materials, from Indiana University http://www.indiana.edu/~c228/c228assignments.html

5. Validity: Deduction • Because deduction is founded on premises that, if formed appropriately, the conclusion must be true, validity and reasonableness are two different things. Therefore, if you don’t accept a premise as true, the conclusion will not work for you. Men are from Mars. John is a man. John is from Mars.

6. Validity: Induction • Because induction is based on patterns, the more often it has been observed, and the closer the link between the evidence and the conclusion drawn, the stronger the argument. Inductive reasoning can be thought of as existing on a continuum. • 25 out of 50 American men like hamburgers. • All men like meat. • Hamburgers might be a good food to offer an American man.

7. Evaluating for Internal Validity • For both deductive and inductive reasoning, certain elements affect the internal process of each type. • However, inductive reasoning, because it is based on patterns, can also be affected by the use of language and the broadness of the conclusion. • The weaker the language of the conclusion, the stronger the reasoning. The conclusion should also make NO claims not explicitly related to the evidence presented. • The results indicate blow darts could be the cause. • The results indicate blow darts ARE the cause.

8. Evaluating for External Validity • Questions to answer include: • What is the norm for this field? For this communication structure? • Anthropology versus primary document • What kind of conclusion is needed or appropriate? • Is it a supposition, or do we need a hard and fast rule? • How does the evidence support this type of reasoning? • What kind of input do we have, and what kind of reasoning will it support? • What type of reasoning is expected for this context? • Lit review, critique, issue paper, philosophical position

9. The Plan • Deduction predominantly structures the whole text or section • The deductive types • Their valid structures • Some practice & application • Induction often functions as evidence, or the culmination of a research project • The inductive types • The strength of their structures • Some practice & application

10. You want holes? • Recognizing structural integrity allows you to • Analyze sources • Lit reviews • Critiques • Caveats/Albeits • Further Research • “Fix-it” • Write better constructed arguments • “Water-tight” logic in argument and support • Reader and writer must agree that premises work for conclusion to work • Clarity of thought and meaning • Firm grasp of relationships and logical progression • Fulfilling the purpose as accurate and appropriate to the situation

11. Deductive Reasoning: Nuts and Bolts • Categorical • Universal • All/none • Non-universal • Some/Some are not JUST BECAUSE SOME ARE, DOES NOT MEAN SOME ARE NOT. The evidence only goes in one direction: what do you know FOR SURE. To draw conclusions with any other understanding violates the structure.

12. Categorical • Which are valid? • Look at the examples, taken from Dr. Wheeler’s wonderful course materials: Wheeler, K. (2011, June 6). Syllogism exercise. Retrieved from http://web.cn.edu/kwheeler/resource_rhet.html

13. Deductive Reasoning: Cont. • Conditional • The only valid forms revolve around an understood relationship: • If the cause happens, the effect MUST happen. • If the cause doesn’t happen, we can’t know 100% the result. • If the effect DOESN’T happen, its cause can’t have happened. • For this instance, this and only this causal relationship has been established, and the effect can’t manifest itself without the cause causing it.

14. Deductive Reasoning ad nauseum • Disjunctive • Either/or • Only valid when one is negated. • Conjunctive • Both cannot • Only valid when one is affirmed. Practice recognizing and analyzing for validity. (Dr. Harris materials)

15. In medias res • A syllogism can act as the dominating structure of a work, as well as fit snuggly among other syllogisms to really hit a point home. • A thesis statement is a conclusion that you will be proving to be correct. • Trees are a natural resource and therefore worth protecting. • All natural resources should be protected. • Trees are natural resources. • Therefore, trees should be protected.

16. Need more support? • Call to make an appointment: • 657-278-2738 • Check out the complete list of our workshops: • On Facebook: • Cal State Fullerton Graduate Students • Grad Studies Website: • http://www.fullerton.edu/graduate/ulc/ • ULC Website: • http://fullerton.edu/ulc/graduate_workshop.asp