Symbolic Logic

Symbolic Logic explores the principles of formal reasoning and the use of symbols to represent logical expressions.

Propositions and Logical ConnectivesTranslating Statements into SymbolsTruth Tables and Logical Equivalence
Predicate Logic and QuantifiersRules of InferenceLogical Fallacies and Invalid Reasoning
Logic in Computer ScienceAnalyzing Arguments in Everyday LifeLogic in Law and Ethics
Building a Logic Study RoutineTackling Complex Arguments Step by Step
Propositions and Log...Translating Statemen...Truth Tables and Log...Predicate Logic and ...Rules of InferenceLogical Fallacies an...Logic in Computer Sc...Analyzing Arguments ...Logic in Law and Eth...Building a Logic Stu...Tackling Complex Arg...
Advanced Topics

Logical Fallacies and Invalid Reasoning

What Are Logical Fallacies?

Logical fallacies are mistakes in reasoning that can make arguments invalid. They can be sneaky and sometimes sound convincing, so it's important to spot them!

Common Fallacies

  • Affirming the Consequent: If \( p \rightarrow q \), and \( q \), wrongly concludes \( p \).
  • Denying the Antecedent: If \( p \rightarrow q \), and \( \lnot p \), wrongly concludes \( \lnot q \).
  • False Dilemma: Pretending there are only two options when there might be more.

Why Does It Matter?

Recognizing fallacies helps you avoid being tricked by bad arguments and makes your own reasoning stronger.

Practice Makes You Sharp

Test yourself by identifying fallacies in everyday arguments or news stories!

Examples

  • Saying 'If you study, you will pass. You passed, so you must have studied'—that's affirming the consequent!

  • 'If it rains, I bring an umbrella. It didn't rain, so I didn't bring an umbrella'—that's denying the antecedent.

In a Nutshell

Logical fallacies are errors in reasoning that make arguments invalid, even if they look convincing.

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Logic in Computer Science