Foundations · Foundation

Logic and Argument

Most arguments you meet, in the news, at work, and in your own head, are never checked. This course gives you the tools to check them. You will learn what makes a deductive argument valid and sound, what makes an inductive argument strong, and how probability decides how much a piece of evidence should move you. You will practise reconstructing what someone actually argued, putting it in its strongest form before you answer it, and finding the missing step. You will learn the standard fallacies by their real names and real examples, and also why the experts who study them warn against using the names as verdicts. The course draws on the textbooks universities assign, the primary texts from Aristotle to Mill and Toulmin, and the psychology of how people actually reason, and it ends with you writing an argument of your own.

What you'll learn

• Identify the premises, conclusion, and missing premise of an argument, put it in standard form, and tell an argument from an explanation, a report, or a bare assertion
• Judge whether a deductive argument is valid and sound by finding a counterexample, using the four conditional forms and a Venn check, and test the link before consulting your opinion of the conclusion
• Judge whether an inductive argument is strong and cogent, whether it generalises from a sample, argues by analogy, claims a cause, or infers the best explanation
• Use natural frequencies, the conjunction rule, base rates, and the likelihood ratio to work out how much a piece of evidence should change your mind, and spot the prosecutor's fallacy
• Reconstruct someone else's argument in its strongest form, with Toulmin's layout and Rapoport's rules, and evaluate it with the acceptability, relevance, and grounds conditions
• Name the standard fallacies, recognise them in documented real cases, and use critical questions to tell a fallacy from the legitimate argument that shares its shape
• Check a news argument for source quality, relative versus absolute risk, survivorship, and your own motivated reasoning, with a repeatable checklist
• Build a one-page written argument that states its strongest objection, concedes or answers it, and survives your own fallacy check and a reader's