1. Thinking critically Arguments, reasons and assumptions

2. “That politician is lying.” “How do you know?” “His lips are moving!” That politician’s lips are moving. [Premise] So: that politician is lying. [Conclusion]

3. Spelling it out... 1.Whenever a politician speaks, s/he is lying. 2.Whenever someone’s lips are moving, s/he is speaking. 3.That politician’s lips are moving. 4.So, that politician is speaking. (from 2 & 3) 5.So, that politician is lying. (from 1 & 4)

4. 1.Whenever a politician speaks, s/he is lying (premise) 2.Whenever someone’s lips are moving, s/he is speaking (premise) 3.That politician’s lips are moving (premise) 4.So, that politician is speaking (from 2 & 3) (intermediate conclusion / premise) 5.So, that politician is lying (from 1 & 4) (conclusion)

5. Argument elements It’s a premise if it gives a reason for a conclusion It’s an intermediate conclusion if it’s both a conclusion from some reasons and also itself a reason for a further conclusion. It’s a conclusion if it’s what reasons are being given for.

6. Reasons: explanation and justification Why are you late for class? Because I didn’t get up when my alarm went off Because my alarm didn’t go off (so it’s not my fault, if it had gone off I’d have been on time...) Please explain... Explain yourself!

7. An argument seeks: to persuade us to believe or to act as indicated in the conclusion on the basis of the premises. Premises are offered as good reasons for the conclusion. Critical thinking asks: “How good?”

8. Assessing arguments critically What are the premises and conclusion? Does the conclusion follow from the premises? (structural / logical) Can the premises be challenged? (dialectical) Are the premises true? What assumptions lie behind them? Are those assumptions the only ones we could make?

9. Some politicians lie Emma is a politician So, Emma lies All politicians lie Emma is a politician So, Emma lies Most politicians lie Emma is a politician So, Emma probably lies

10. The argument from design (per Hume) 1. The world is like a highly complex machine. 2. All instances of such machines which we have encountered have been products of intelligence and design. 3. So the world is (very probably) a product of intelligent design. 4. If the world is the product of design, it is a product of human or superhuman intelligence. 5. The world is not a product of human intelligence. 6. So, the world is (very probably) the product of superhuman intelligence.

11. Underlying assumptions The complex adaptedness of the world can only be explained as something made on purpose. Evidence of lack of purpose (e.g. random destruction and slaughter) is suppressed. “God” is backstage waiting to come on. (superhuman intelligence = Deity = a single, benevolent intelligence...)