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Introduction to Propositional Logic

This is a free course I have made available through my YouTube channel. The textbook I use is Nicholas J. J. Smith's Logic: The Laws of Truth.

https://youtu.be/-HZp0XnmEXI
1 Propositions and Arguments

Read 1.1 What is logic? (pp. 3-4)

What is logic? How is it different from good reasoning?

Read 1.2 Propositions (p. 5-6)

What is a proposition? What is truth?

Do 1.2.1 Exercises (p. 6)

Can you tell which one is a proposition?

Optional: Read 1.2.2 Sentences, Contexts, and Propositions (pp. 6-8)

Optional: What is the difference between a type and a token?

Optional: Read 1.2.2 Sentences, Contexts, and Propositions (pp. 8-10)

Optional: Is a proposition a sentence type? A sentence token?

Optional: Read 1.2.2 Sentences, Contexts, and Propositions (pp. 10-11)

Optional: What elements make up our communication?

Read 1.3 Arguments (pp. 11-13)

What is a logical argument? Why is it useful?

Do 1.3.1 Exercises (pp. 13-14)

Can you identify the argument?

Read 1.4 Logical Consequence (pp.14-21)

What is a logical consequence? What is validity?

Read 1.4 Logical Consequence (pp. 19-21)

What is good reasoning?

Do 1.4.1 Exercises (p. 21)

Can you tell a valid argument from an invalid one?

Read 1.5 Soundness (pp. 21-23)

What is a sound argument? How is it different from a valid argument? Or a true argument?

Do 1.5.1 Exercises (p. 23)

Can you tell the difference between a valid argument and a true one?

Read 1.6 (pp. 23-24)

What is a connective? What is 'truth-functional'?

Read 1.6.1 Negation (pp. 24-26)

What is a negation? Negand?

Do 1.6.1.1 Exercises (p. 26)

Can you tell what has been negated?

Read 1.6.2 Conjunctions (pp. 26-27)

What is a conjunction?

Do 1.6.2.1 Exercises (p. 27)

Can you discern the two claims of a conjunction?

Read 1.6.3 Disjunction (pp. 27-28)

What is a disjunction?

Read 1.6.4 Conditional (pp. 28-29)

What is a conditional?

Do 1.6.4.1 Exercises (p. 29)

Can you identify the antecedent and consequent?

Read 1.6.5 Biconditional (pp. 30-31)

What is a biconditional?

Do 1.6.6 Exercises (p. 31)

How do you pick out the connectives?

2 The Language of Propositional Logic

Read 2.1 Motivation (p. 32)

Why make logic full of weird symbols and formulas?

Read 2.2 Basic Propositions of PL - 2.2.1 Glossaries (pp. 32-35)

How do I symbolize basic propositions? Sentence letters

Read 2.3.1 Negation - 2.3.2 Conjunction

Do 2.3.3 Exercises (pp.36-37)

How do I symbolize negation and conjunction?

Read 2.3.4 Disjunction

Do 2.3.5 Exercises (pp. 36-37)

How do I symbolize a disjunction?

Read 2.3.6 Conditional, 2.3.7 Biconditional

Do 2.3.5 Exercises

Read 2.3.9 Review (pp. 37-39)

How do I symbolize conditionals and biconditionals?

Read 2.4 Wff Variables, 2.5 Syntax of PL (pp. 39-42)

What is syntax?

Do 2.5.1 Exercises Question 1 (p. 42)

What is a well-formed formula (WFF)?

Do 2.5.1 Exercises Question 2 (p. 42)

What is a recursive definition?

Read 2.5.2 Logical and Nonlogical Vocabulary

Logical v. non-logical v. auxiliary symbols?

Read 2.5.3 Constructing Wffs; do 2.5.3.1 Exercises (pp. 42-44)

How do I construct WFFs? How can I tell which is the main connective?

Read 2.5.4 Abbreviations, Do 2.5.4.1 Exercises (pp. 44-47)

Tips for writing propositions

Read 2.5.5 Polish Notation; Do 2.5.5.1 Exercises (pp. 47-48)

What is Polish Notation?

Read 2.5.6 Finite Alphabets (p.48)

Do we have an infinite amount of symbols?

3 Semantics of Propositional Logic

Read the first two paragraphs of Chapter 3 (p. 49)

What is the Principle of Bivalence?

Read 3.1 Truth Tables for the Connectives

Intro to Truth Tables

Read 3.2 Truth Values of Complex Propositions

Do 3.2.1 Exercises

What's the truth value of complex propositions?

Read 3.3 Truth Tables for Complex Propositions

Do 3.3.1 Exercises

Truth Tables for Complex Propositions

Read 3.4 Truth Tables for Multiple Propositions

Do 3.4.1 Exercises

Truth Tables for Multiple Propositions

Read 3.5 Connectives and Truth Functions

Do 3.5.1 Exercises

What is a truth-functional connective?

Read 4.1 Arguments & sub-sections

4 Uses of Truth Tables

Read 4.1 Arguments, 4.1.1 Counterexamples, 4.1.3 Soundness

Do 4.1.2 Exercises

Truth Tables and Valid Arguments

Read 4.2 Single Propositions

Do 4.2.1 Exercises

What is a tautology? A contradiction?

Read 4.3 TwoPropositions

Do 4.3.1 Exercises

Contraries, Contradictories, Equivalences, and Joint Satisfiability

Read 4.3.2 More Abbreviations

Why ∧ and ∨ Strings Are Okay, but Not → or ↔︎

4.4 Sets of Propositions

Do 4.4.1 Exercises

Satisfiable Sets of Propositions

Read 4.5 More on Validity

How truth tables show validity

5 Logical Form

Read 5, 5.1 Abstracting from Content

Do 5.1.1 Exercises

What is the form of an argument (and why should I care)?

Read 5.2 Instances: From Forms to Propositions

Do 5.2.1 Exercises

What is an instance of a form?

Read 5.3 Argument Forms

Do 5.3.1 Exercises

What is the form of an argument?

Read 5.4 Validity and Form, 5.5 Invalidity and Form

Do 5.4.1 and 5.5.1 Exercises

How validity isn't the same for argument forms

Read 5.6 Notable Argument Forms

Modus Ponens, Affirming the Consequent, Modus Tollens, Denying the Antecedent

Hypothetical Syllogism

Constructive Dilemma

Disjunctive Syllogism

Read 5.7 Other Logical Properties

How do logical properties relate to each other?

6 Connectives: Translation and Adequacy

Read 6.1 Assertibility and Implicature

What is Conversational Implicature?

Read 6.2 6.2 Conjunction

Ands that Aren't Conjunctions?

Read 6.3.1 Indicative and Counterfactual Conditionals

Counterfactual vs. Material Conditionals

Read 6.3.2 Indicative and Material Conditionals

Is the indicative conditional the same as the material conditional?

Read 6.3.3 Conditional and Biconditional without "If"

The Logic of 'Unless'

Read 6.3.4 "If" without Conditional

Biscuit Conditionals

Read 6.4 Disjunction

Exclusive Disjunctions

Read 6.5 Negation

Do 6.5.1 Exercises

De Morgan's Laws

Read 6.6 Functional Completeness

Defining connectives with other connectives

Read 6.6.2 The Range of Possible Connectives

All Possible Connectives

Read 6.6.2 The Range of Possible Connectives

Functionally Complete Sets of Connectives

Do 6.6.3 Exercises

How can we tell if a set of connectives is functionally complete?

7 Trees for Propositional Logic

Read 7 Trees for Propositional Logic, 7.1 Tree Rules, 7.2 Applying the Rules

What are truth trees?

Read 7.3.1 Validity

Do 7.3.1.1 Exercises

Validity with Truth Trees

Read 7.3.2 Satisfiability

Do 7.3.2.1 Exercises

Satisfiability with Truth Trees

Read 7.3.3 Contraries and Contradictories

Do 7.3.3.1 Exercises

Contraries and Contradictories with Truth Trees

Read 7.3.4 Tautologies

Do 7.3.4.1 Exercises

Tautologies with Truth Trees

Read 7.3.5 Equivalences

Do 7.3.5.1 Exercises

Read 7.3.6 Summary

Equivalence with Truth Trees

Read 7.4 Abbreviations

Truth Trees and Abbreviations

Material Fallacies

Material (informal) fallacies of reasoning are not errors in the structure of an argument, but in what is assumed. 

Argumentum ad Verecundiam: Appeal to Illegitimate Authority

Argumentum ad Populam (Popular Appeal)

Ad hominem

Equivocation

Begging the Question

Reader Interactions