Types of reasoning…Types of reasoning…

DeductiveDeductive Those aimed at validity…attempt to convince us Those aimed at validity…attempt to convince us

of the conclusion using linked premises (i.e. the of the conclusion using linked premises (i.e. the premises directly link to the conclusion).premises directly link to the conclusion).

InductiveInductive Attempt to generalise from evidence – offer a Attempt to generalise from evidence – offer a

conclusion about all things of a type by making conclusion about all things of a type by making observations about a limited number of things of observations about a limited number of things of that type.that type.

DeductiveDeductive

(p1) All oranges are fruits(p1) All oranges are fruits

(p2) All fruits grow on trees(p2) All fruits grow on trees

(c) Therefore, all oranges grow on trees(c) Therefore, all oranges grow on trees

(p1) All bachelors are single(p1) All bachelors are single

(p2)Johnny is single,(p2)Johnny is single,

(c) Hence, Johnny is a bachelor(c) Hence, Johnny is a bachelor

InductiveInductive

(p) All of the Harry Potter books have been good.(p) All of the Harry Potter books have been good.(c) Therefore, the next Harry Potter book will also be good. (c) Therefore, the next Harry Potter book will also be good.

(p1) All shops in the UK took £ sterling yesterday.(p1) All shops in the UK took £ sterling yesterday.(p2) All the shops in the UK took £ sterling before yesterday (p2) All the shops in the UK took £ sterling before yesterday

and for as long as I can remember as well.,and for as long as I can remember as well.,(c) Therefore, all shops in the UK will take £ sterling (c) Therefore, all shops in the UK will take £ sterling

tomorrow.tomorrow.

(p)The sun rose yesterday, and everyday before that for as (p)The sun rose yesterday, and everyday before that for as long as the Earth has existed.long as the Earth has existed.

(c) Therefore, the sun will rise tomorrow.(c) Therefore, the sun will rise tomorrow.

Unreliable ArgumentsUnreliable ArgumentsFallaciesFallacies

General IntroductionGeneral Introduction

Fallacies are types of arguments that Fallacies are types of arguments that display errors in reasoning of a certain display errors in reasoning of a certain kind. kind.

Fallacies are Fallacies are genuine genuine arguments: real arguments: real attempts to persuade us to accept the attempts to persuade us to accept the conclusion based on the premises.conclusion based on the premises.

P.51-52P.51-52

TasksTasks

1. Re-read about explain, in detail, inductive 1. Re-read about explain, in detail, inductive and deductive arguments.and deductive arguments.

2. Re-read and explain ‘affirming the 2. Re-read and explain ‘affirming the consequent’ and ‘denying the antecedent’ consequent’ and ‘denying the antecedent’ in detail (use the structure examples to in detail (use the structure examples to help you outline these.help you outline these.

Next time in Philosophy…Next time in Philosophy…

In pairs/threes:In pairs/threes:

Create a short (1-1 ½ minutes) Create a short (1-1 ½ minutes) presentation on the type of fallacy you presentation on the type of fallacy you draw from the FALLACY HAT draw from the FALLACY HAT

Your choice of format – PPT, STORY Your choice of format – PPT, STORY BOARDS…surprise me. BOARDS…surprise me.