ARGUMENTATION & LOGIC

1. ARGUMENTATION & LOGIC Speaker’s Development, Week 9 Karolien Michiels

2. Arguments versus assertions Argument • … a set of sentences such that… • … one of them is being said to be true… • … the other(s) are being offered as reasons for believing the truth of the one. → arguments are good or bad

3. Arguments versus assertions Assertion • are said without any justification as to why we can accept them to be true • they sometimes look like arguments → assertions are true or false ‘All countries should strive to become true democracies.’

4. Exercise 1: Are these arguments? • Do the following extracts contain arguments? If yes, what is the conclusion?

5. Good vs. bad arguments In a good argument… • the conclusion follows from the premises & • the premises are all true. Examples of bad arguments: • Tomorrow the sun will shine because my mum called me. • Because tomorrow is Valentine’s day and Valentine’s day makes everyone happy, tomorrow everybody will be happy.

6. Bad reasoning: Fallacies • A fallacy is an argument that uses poor reasoning. • An argument can be fallacious whether or not its conclusion is true. • Judges spot them. Don’t. • If your opponents use them: • Briefly dismiss the obvious ones • Point out the insidious ones

7. Types of fallacies • Inconsistency: something inconsistent or self-defeating has been proposed or accepted. • Inappropriate presumption: we have an assumption or a question presupposing something that is not reasonable to accept in the relevant conversational context. • Relevance: irrelevant reasons are being invoked or relevant reasons being ignored. • Insufficiency: the evidence supporting a conclusion is insufficient or weak.

8. Other fallacies: Red Herrings (irrelevant, distracting arguments) & Bad Consequences (I don’t like the implications so it can’t be true)

9. Exercise 2: Fallacies • Explain whether and why the following statements are fallacies.

10. More examples • Circular logic:Where your argument consists of two parts, the first being a statement, and the second being your conclusion, and yet your statement is what you are trying to prove; • The Bible is true and hence you should obey the word of God. • Victim’s should receive justice and hence we should have the death penalty. Think of it like this- A circular argument is where you make the same statement twice, but with slightly different wording.

11. Even more examples. • Slippery slope: This is where you claim the current motion will lead to a future outcome: If we legalise Marijuana next thing we’ll legalise heroin • Strawman: This is where you exaggerate the other’s argument: (P1): I support the NHS (P2): So you support communism? Because that works so well in China.

12. More again • Ad Hominem: Latin for ‘against man’This is where you attack your opponent rather than their argument. (P1) I oppose elections as they simply don’t represent people’s actual views.(P2) Well you clearly don’t understand elections then. • IMPORTANT: If this is done at a competition you will be thrown out. • MORE IMPORTANT: If P2 were to say “Respectfully Mr Speaker it is the view of the opposition that the Government has not quite grasped the current stance on elections or the alternatives open to the current stance.” This would probably be fine. • If you do the second Ad Hominem then you’ll likely only just be asked to apologise rather than be kicked out, so it covers you like that to.

13. Yep…. Even more • Ad Populum: Meaning popular: (P1): “In surveys recently taken it has been shown that most people oppose Marijuana being illegal.” • Why should the judge care what most people want? You can try explaining why if you want. • Do people always want what's best for them?

14. Guess what? • No more examples

15. I lied • Appeal to Authority:This is simple where somebody claims because a person is heavily qualified they have to be accepted as right. (P1) Lord Denning (A highly influential judge) took the view that juries are extremely important. • So? Are you seriously claiming that highly educated people are never wrong? • THIS ONE IS MAJORLY COMMON • The fallacy can be avoided if you sufficiently back up that person’s view, for instance: You can make the claim Juries are great then point to judges who agree and explain why their support backs you up.

16. More • Appeal to ignorance: More or less the exact opposite of the previous: (P1) There is no evidence that Alien’s exist therefore they don’t. • 2 Flaws here • What if nobody has checked? • (P1) Very little trials result in the conclusion that the victim has actually lied. • That is true, but trials don’t ask if the victim has lied. • Does a lack of evidence mean there is no ground to make a statement? • The Drake equation states how many habital planets there are in the galaxy. This is not evidence of aliens but states it is highly improbable that aliens do not exist. KEEP IN MIND: The burden of proof rests on those making a positive claim, if somebody was arguing aliens do exist but provides no evidence then this is a grounds for criticism.

17. More • Personal Incredulity • This is effectively any use of a subjective term. • That’s Immoral! • No reasonable person could believe that!! • Really? Says who? How could you possible back any of that up? AVOID MORALITY AT ALL COSTS!!!

18. More • Ad Hoc (‘For the purpose’) Otherwise known as ‘no true Scotsman’ • (P1) No pill would ever cause side affects. • (P2) What about these 5 examples • (P1) They must have been bad pills. • Or • (P1) No Scotsman doesn’t eat porridge. • (P2) My gran is Scottish and she doesn’t • (P1) No TRUE Scotsman • You cannot change the topic of the debate after you have stated it. • Unless you are clarifying. • Basically just be careful and explain properly.

19. Even more • Non SequiturLatin: Does not follow – Not in Sequence • In some ways every logical fallacy is this, however sometimes you receive an argument that falls into no other category. • (P1) I killed a mouse the other day and now it’s raining. If I kill a mouse it will lead to rain. • (P2) What the hell is wrong with you? • In short: BACKUP YOUR STATEMENTS.

20. Final one (I promise this time) • Unstated points. • Example: • If we label foods with their cholesterol content, Americans' will make healthier food choices. • Unstated premises: • cholesterol in food causes cholesterol in people. • better food labelling will reduce Americans' cholesterol intake • having high cholesterol is a bad thing • people make food buying decisions based on food labels • Remember: Presume the judge is an idiot.

21. Now, not an example • Explain why the following are fallacious, and list the fallacies you spotted: -The Bible states God exists, therefore God exists. -Brexit will be good for Democracy -Science says for something to exist it must come from something, what caused the big bang? It has to be god. -If Wales goes independent Scotland would go independent, nobody would want that. -Yeah but torturing people goes against Human Rights. -The Majority want Brexit, therefore we should commit to Brexit. -If we armed all Police this would lead to a massively higher rate of killings.