Logic: Deduction, Induction, and Fallacies

• The presentation covers logic concepts, deduction, induction, and fallacies, among others.
• It was prepared by AP. Dr. Mohd Nuri Al-Amin Endut.

Introduction

• Topics covered are attendance using PowerApps, a quiz, and a review of Chapter 2 covering Philosophy in Life.

Learning Outcomes

• Able to explain the role, position, and relationship between logical science and philosophy.
• Able to explain various errors of thought, arguments or fallacies.
• Able to describe the development, uses, and differences between deduction and induction.
• Able to describe the variety of methodologies that enrich the development of more complex sciences.

What is Logic?

• Greek word logos translates to word, discussion, intellect, rule and reason.
• Logic distinguishes between good and bad reasoning, by examining normative criteria for valid conclusions and demonstrations.
• Logic studies arguments that consist of a premise and a conclusion.
• Arguments consist of a sequence of premises that leads to a conclusion.
• Arguments are not the same as opinions.
• Arguments contain a sequence of statements that leads to a conclusion.
• A proposition that is an assertion or statement can be true or false.
• If all premises are true and the conclusions drawn are true, then the argument is valid.

Deduction

• Arguments in which binding conclusion are drawn from the premise.
• Specific conclusions are drawn from the general statements
• Premise 1: All human beings will die.
• Premise 2: I am a human being.
• Conclusion: So, I will die.

Induction

• Arguments in which a conclusion seems likely to occur is drawn from the premise.
• General conclusions are drawn from specific statements.
• Premise 1: 90% of students in public university do not proficient in English.
• Premise 2: Zubaidah is a student at a public university.
• Premise 3: Therefore, Zubaidah may not be fluent in English.

Comparison between Deductive vs Inductive Reasoning

• Deductive reasoning deduces new information from known facts and information; inductive reasoning makes generalizations using specific facts.
• Deductive reasoning follows a top-down approach, whereas inductive reasoning follows a bottom-up approach.
• Deductive reasoning starts from the premises, whereas inductive reasoning starts from the conclusion.
• Deductive reasoning must be true if the premises are true; Inductive reasoning does not guarantee the truth of conclusions.
• Deductive reasoning is difficult and requires true facts; inductive reasoning is fast, easy, and needs evidence.
• Deductive reasoning process: theory→ hypothesis→ patterns →confirmation; inductive reasoning process: observations →patterns→hypothesis→theory.
• Deductive reasoning arguments may be valid or invalid; inductive reasoning arguments may be weak or strong.
• Deductive reasoning goes from general facts to specific facts, whereas inductive reasoning goes from specific facts to general facts.

Abductive Reasoning

• Incomplete observations lead to best prediction, which may be true.
• Other methods of thinking in philosophy include the abduction method and the heuristic method.
• Abduction or inference is the best explanation for the appearance of a phenomenon.
• Conclusions are drawn about what happened before the existence of what can explain why the phenomenon occurs.
• In other words, the best explanation based on the phenomenon in question is given by thinking backwards or upside down.
• For example, a car is observed driving on the road, questions are asked: How can this happen? What makes the car move?
• Need to determine what conditions must exist for the phenomenon of a moving car to occur.

Heuristic

• Inductive, deductive logic, and abduction can be used to think logically and are applicable to thought.
• Heuristic method differs from the other methods because it does not have systematic or ordered rules like deductive and inductive logic.
• Differentiates or makes heuristics a different kind of thinking than any other logical thinking.
• This logic has no specific rules, but has guidelines to implement heuristic thinking.
• Heuristic thinking is exploratory; is not an evaluation of nature as found in deductive and inductive logic.
• The method of logic is used to evaluate whether an argument or a proposition can be accepted as valid or invalid.

Fallacy

• False arguments are used to deceive or trick people into believing something is true.
• Functional logic distinguishes a failing argument from a valid argument.

Why fallacies occur?

• Insufficient data or facts.
• Prejudice and pessimism.
• Distorted conclusions.
• Wrong assumptions.
• Stress.
• Coercion.

Types of Logical Fallacies

• Strawman: Misrepresenting an argument to make it easier to attack.
• False cause: Presuming a relationship between things means one causes the other.
• Slippery slope: Asserting that allowing one thing will lead to an extreme consequence.
• Special pleading: Moving the goalposts to create exceptions when a claim is proven false.
• Ad hominem: Attacking an opponent's character to undermine their argument.
• Loaded question: Asking a question with a built-in assumption of guilt.
• Appeal to emotion: Manipulating an emotional response instead of a valid argument.
• The fallacy fallacy: Presuming a claim is wrong because it's poorly argued.
• Tu quoque: Avoiding criticism by turning it back on the accuser.
• Burden of proof: Claiming the burden of proof lies on someone else to disprove your claim.
• Personal incredulity: Dismissing something as untrue because you find it difficult to understand.
• Ambiguity: Using double meanings of language to mislead or misrepresent.
• Gambler's fallacy: Believing "runs" occur in statistically independent phenomena.
• Bandwagon: Appealing to popularity as validation.
• Appeal to authority: Using an authority figure's opinion in place of an argument.
• Begging the question
• Appeal to nature
• Composition/division: Assuming what's true of one part applies to all or other parts.
• Anecdotal
• No true Scotsman

Categories of Fallacy

• General fallacy
• Accident
• Ad nauseam
• Loaded question
• Middle ground
• Black-or-white/Dilemma
• Ignorance
• Labeling
• Abusive
• Convoluted argument
• Figure-of-speech
• Coincidence
• Cliche
• Emotional fallacy
• Appeal to novelty
• Appeal to pity
• Special pleading
• Genetic fallacy
• Ad Hominem
• Ad Populum
• Appeal to authority
• Inference
• Composition
• Division