- Fallacy Files, The
Describes and gives examples of logical fallacies from the media and everyday life.
- Logical Fallacies
Explores and defines errors of reasoning.
- Association for Symbolic Logic
International organization supporting the presentation, publication, and critical discussion of scholarly work in the field of logic.
- Wikipedia: Modal Logic
User-created article explaining modal logic, the logic of possibility. Explains the difference between modal and other logics, modal operators, the formal rules of modal logic, and the development of the system.
- Critical Reasoning Tutorial
Interactive tutorial aimed at introducing students to the basics of argument structure and logic.
- Logician, The
Features logic, philosophy, epistemology, phenomenology, psychology, and theology writings by Avi Sion, Ph.D.
- Nizkor Project: Fallacies
Describes several logical fallicies.
- Stephen's Guide to the Logical Fallacies
Describing errors of reasoning which may be recognized and corrected by prudent thinkers.
- Mission: Critical
Interactive college-level virtual lab that teaches the basic concepts of critical thinking and informal logic, such as induction, deduction and fallacies.
- Factasia Logic
Technical and philosophical information concerning symbolic logic and its applications.
- Papers on Probabilistic Logic
Features articles by Richard Jeffrey and John Dorling.
- Centre for Logic and Philosophy of Science
Focuses on research in paraconsistent logic, inconsistency-adaptive logic, non-standard logic, causal explanation, scientific discovery, and methodology.
- Ariadne's Thread
Critical examinations of ethical controversies including topics like abortion, hate speech, and justice.
- On the Model Theory of Knowledge
Offers a language for expressing the operator 'knowing that' with axioms and rules of inference and a Kripke type of semantics.