Business Thinking

1. Business Thinking Some Principles of Logic

2. Business ThinkingAPEL: Some principles of Logic • Termsa word or combination of words that can stand by itself as the subject or predicate of a proposition • Silence is Golden (Both are terms)

3. Business Thinking APEL: Some principles of Logic • Propositionthat which can be affirmed or deniede.g. Silence is Golden • Silence is the subject • Golden is the predicate

4. Business Thinking APEL: Some principles of Logic • Argumentis a series of logically related propositions • All men are mortal (Major premise) • Socrates was a man (Minor premise) •  Socrates was mortal (Conclusion)

5. Business Thinking APEL: Some principles of Logic • DEDUCTION (from the general to the particular) • If the premises are true and the argument is valid then the argument must be true • All of the information is contained (at least implicitly) in the premises

6. Business Thinking APEL: Some principles of Logic • INDUCTION (inference of a general condition from a set of observed instances) • If the premises are true then the conclusion is probably but not necessarily true • The conclusion contains information not present, even implicitly, in the premises

7. Business Thinking APEL: Some principles of Logic • TRUTHconcerns the factual correctness or otherwise of the premises • VALIDITY refers to whether the conclusion is correctly drawn (according to the rules of logic) from the premises • Propositions are true or false; arguments are valid or invalid (these terms are not inter-changeable)

8. Business Thinking APEL: Some principles of Logic • Deductive logic is concerned with the construction of rules for the production of valid arguments (and the exposure of invalid ones) • NB an invalid argument might have a true conclusion (making it harder to spot) and a valid argument might have a false conclusion

9. Business Thinking APEL: Some principles of Logic • Valid and true All cats have four legs My pet is a cat  my pet has four legs • Invalid and true The industrious are prudent Ants are prudent Ants are industrious

10. Business Thinking APEL: Some principles of Logic • Valid and false All fish are cold-blooded Whales are fish Whales are cold-blooded • Invalid and false All cats have tails My hamster has a tail My hamster is a cat

11. Business Thinking APEL: Some principles of Logic • Construct two arguments…. • One which is valid but has a false conclusion • One which is invalid but in which all of the prepositions are true

12. Business Thinking APEL: Some principles of Logic • IF-THEN • Affirming the antecedent (VALID) If (and only if) p, then q p q • Denying the Consequent (VALID) If (and only if) p, then q Not q not p

13. Business Thinking APEL: Some principles of Logic • IF-THEN • Affirming the consequent (INVALID) If p, then q q p • Denying the Antecedent (INVALID) If p, then q Not p not q

14. Business Thinking APEL: Some principles of Logic IF and IFF • IF is an ambiguous word…. • (a) If I pass my exams, I will be a graduate • (b) If I win the pools, I will become rich • In (a) IF means if and only if (sometimes Iogicians call this IFF) • In (b), there are are other ways of becoming rich (e.g. by inheritance)

15. Business Thinking APEL: Some principles of Logic SOME and ALL • English is imprecise .. When we say All cats are mammals we are really saying… • All cats are (some of the entire category) of mammals

16. Business Thinking APEL: Some principles of Logic Contradictions… • To deny that All cats are mammals we do not go to the opposite extreme and say No cats are mammals • The existence of one, egg-laying cat is sufficient for us to argue that Not all cats are mammals without going to the opposite extreme of saying No cats are mammals

17. Business Thinking APEL: Some principles of Logic SYLLOGISMS • Are a triad of connected propositions that have to follow the rules of logic. • When these rules are broken, we have examples of fallacies

18. Business Thinking APEL: Some principles of Logic Fallacy of the undistributed middle • All followers of Tony Blair love opera • I am a lover of opera • Therefore I am a follower of Tony Blair

19. Business Thinking APEL: Some principles of Logic Fallacy of the illicit process • Some clever men are eccentric • Smith is not eccentric • Therefore Smith is not a clever man

20. Business Thinking APEL: Some principles of Logic Fallacy of the Two Middle Terms • Chalk is different from cheese • Cheese is different from butter • Therefore butter is different from chalk

21. Business Thinking APEL: Some principles of Logic Valid argument form: Reductio ad absurdum • To prove: p • Assume not-p • Deduce a false statement • Conclude that if not-p is false, then p must be true • Used extensively in mathematics where it is known as indirect proof

22. Business Thinking APEL: Some principles of Logic Valid argument form: The dilemma • Either p or q • If p, then r • If q, then s • Either r or s

23. Business Thinking APEL: Some principles of Logic Theological example • There is evil in the world • Either God cannot prevent evil or he does not wish to • If God can’t prevent evil, he is not all-powerful • If God does not want to prevent evil, he is not benevolent • Therefore God is not all powerful or he is not benevolent

24. Business Thinking APEL: Some principles of Logic Fallacies of Deduction Affirming the Consequent • If p then q; q;  p • If we play good football, we will win • We have won • Therefore we played good football

25. Business Thinking APEL: Some principles of Logic Fallacies of Deduction Denying the antecedent • If p then q; not p;  not q • If Jeffrey Archer testifies, he is innocent • Jeffrey Archer is not willing to testify •  Jeffrey Archer is not innocent

26. Business Thinking APEL: Some principles of Logic Fallacies of Induction Insufficient statistics • Every cat I have seen has a tail •  all cats have tails

27. Business Thinking APEL: Some principles of Logic Fallacies of Induction Biased statistics • Every time, I wait for a bus there are always buses going in the opposite direction • Therefore there are always more buses going in the opposite direction

28. Business Thinking APEL: Some principles of Logic Causal fallacies Post hoc, ergo propter hoc • B was caused by A because B followed A

29. Business Thinking APEL: Some principles of Logic Causal fallacies Confusion of cause and effect • Sober students have money • Drunk students have no money •  give drunk students money to make them sober

30. Business Thinking APEL: Some principles of Logic Causal fallacies Common cause • When it’s cold, I put on warm clothes • When it’s cold, I catch a cold •  Warm clothes give me a cold

31. Business Thinking APEL: Some principles of Logic Equivocation • Only man has a sense of humour • No man is a woman • No women have a sense of humour

32. Business Thinking APEL: Some principles of Logic Petitio Principii (lit. Asking for the Principle Or ‘Begging the Question’) Assuming what we should be trying to prove but is this true in this case ? • All true pleasures lead to happiness • All unselfish acts are true pleasures •  all unselfish acts lead to happiness

33. Business Thinking APEL: Some principles of Logic Exercises (1 of 6) • If the Tories win the next by-election, they will win the general Election • If they lose the by-election, it follows they will not win the General Election

34. Business Thinking APEL: Some principles of Logic Exercises (2 of 6) • Since no monetarists were Keynesians and Margaret Thatcher was not a Keynesian, then Margaret Thatcher was a monetarist

35. Business Thinking APEL: Some principles of Logic Exercises (3 of 6) • An increase in the money supply leads to inflation • So the way to cure inflation is to curb the money supply

36. Business Thinking APEL: Some principles of Logic Exercises (4 of 6) • All BAMBA students work hard • All students who work hard pass their examinations •  All BAMBA students will pass their examinations

37. Business Thinking APEL: Some principles of Logic Exercises (5 of 6) • BAMBA students who hate logic are intelligent • BAMBA students who hate logic will not fail their exams • As those who are not intelligent fail their exams

38. Business Thinking APEL: Some principles of Logic Exercises (6 of 6) • Marx’s theories cannot be taken seriously since his prediction that there would be an increasing degree of polarisation and concentration into opposing classes is ridiculous