Learn Logic
Master first-order logic through progressive challenges. Start with the basics and work your way up to advanced reasoning.
First Steps
Get comfortable with logic. Learn what arguments are, how to spot good reasoning, and the classical foundations.
1.Introduction
Learn foundational concepts: what logic is, valid vs. invalid arguments, and sound reasoning.
2.Syllogistic Logic
Translate English into syllogistic notation. Master the classical form of logical reasoning.
3.Meaning and Definitions
Understand uses of language, types of definitions, and the analytic/synthetic distinction.
4.Fallacies and Argumentation
Identify good arguments vs. fallacious reasoning. Master informal fallacies.
5.Inductive Reasoning
Master probability, analogical reasoning, Mill's methods, and inference to best explanation.
Building Blocks
Building Blocks
Master the core of formal logic. Propositional connectives, truth tables, and proof construction.
1.Basic Propositional Logic
Master AND, OR, NOT, and IF-THEN connectives. Truth tables, S-rules, and I-rules.
2.Propositional Proofs
Construct formal proofs and refutations. Learn natural deduction and truth trees.
Expanding Horizons
Expanding Horizons
Explore richer logical systems. Quantifiers, modality, obligations, and beliefs.
1.Basic Quantificational Logic
Master universal and existential quantifiers. Translations, proofs, and refutations.
2.Relations and Identity
Extend predicate logic with identity and relations. Handle definite descriptions.
3.Basic Modal Logic
Explore possibility and necessity operators. Express what could be or must be true.
4.Further Modal Systems
Advanced modal systems including quantified modal logic and temporal operators.
5.Deontic and Imperative Logic
Reason about obligation, permission, and prohibition. The logic of ethics and law.
6.Belief Logic
Express beliefs, knowledge, willing, and rationality. Model propositional attitudes.
Mastery
Mastery
Deep understanding. The philosophy, history, and frontiers of logical thought.
1.A Formalized Ethical Theory
Apply logic to ethics: practical reason, consistency, and the golden rule formalized.
2.Metalogic
Study logic about logic: soundness, completeness, and Gödel's incompleteness theorem.
3.History of Logic
Trace logic from Aristotle through Frege, Russell, and modern developments.
4.Deviant Logics
Explore non-classical logics: many-valued, paraconsistent, intuitionist, and relevance logic.
5.Philosophy of Logic
Examine philosophical foundations: abstract entities, truth, paradoxes, and logic's scope.