508556 - EPISTEMOLOGY, LOGIC AND INFORMAL REASONING

The course provides an introduction to informal logic, syllogistic logic, and epistemology. It combines the study of fundamental concepts and methods with the practical analysis, reconstruction, and evaluation of arguments drawn from a variety of contexts.

The first part of the course is devoted to informal logic and argumentation. It introduces the notions of sentence, statement, proposition, premise, conclusion, inference, and argument. Particular attention is paid to the challenges posed by natural language, including ambiguity, vagueness, context sensitivity, implicit premises and conclusions, and the distinction between arguments and explanations. Students learn how to identify arguments in ordinary discourse, reconstruct them in canonical form, and represent the structure of simple and complex arguments by means of argument diagrams.

The course then examines the distinction between deductive and non-deductive reasoning. Deductive arguments are assessed through the notions of validity, invalidity, counterexample, soundness, and the distinction between the truth of propositions and the validity of arguments. Students are introduced to common valid forms of inference, including modus ponens, modus tollens, disjunctive syllogism, and hypothetical syllogism.

The treatment of non-deductive reasoning covers inductive strength, well-foundedness, and the defeasible character of inductive conclusions. The principal forms examined include statistical syllogisms, statistical and inductive generalisations, arguments from analogy, abductive reasoning or inference to the best explanation, and causal reasoning. The discussion of causal inference includes the concepts of necessary and sufficient conditions and an introduction to Mill’s methods.

A further section is devoted to the critical evaluation of arguments and to strategies for constructing counterarguments. Students learn how to challenge premises, identify counterexamples, assess the strength of inferential support, introduce relevant defeating information, and formulate arguments supporting an opposing conclusion. The course also introduces major families of fallacies, including semantic fallacies, formal fallacies, inductive fallacies, fallacies of presumption, and fallacies of relevance. Examples include ambiguity, vagueness, denying the antecedent, affirming the consequent, slippery-slope reasoning, hasty generalisation, neglect of base rates, false analogy, the gambler’s fallacy, circular reasoning, ad hominem arguments, appeals to inappropriate authority, appeals to ignorance, and the straw man fallacy.

The second part introduces the theory of categorical syllogisms. It addresses categorical propositions, immediate inferences, syllogistic reasoning, and more complex chains of syllogistic inference. The emphasis is on recognising their logical structure and determining whether the conclusions follow from the premises.

The final part offers a concise introduction to epistemology. It examines central epistemic notions such as belief, knowledge, justification, and truth. Different forms of knowledge are distinguished, including knowledge by acquaintance, practical knowledge or “knowing how,” and propositional knowledge or “knowing that.” The traditional analysis of propositional knowledge as justified true belief is presented alongside the problem of epistemic luck and the Gettier problem.

The course concludes with a discussion of theories of epistemic justification, including deontological and non-deontological conceptions, evidentialism, and reliabilism. It also considers the structure of justification through the contrast between foundationalism and coherentism, and introduces the correspondence and coherence theories of truth.