Logic, Fallacies, and Reasoning: Key Concepts for Critical Thinking

What is the Law of Noncontradiction?

Something can't be A and non-A in the same sense and time.

What is the first tool in the thinking toolbox?

Just because someone tells you something doesn't make it true.

What is direct evidence?

Eyewitness evidence.

What is circumstantial evidence?

Everything else.

What is corroborating evidence?

Evidence that strengthens already existing evidence.

What are the 3 structural parts of Logic?

Terms, propositions, arguments.

What makes an argument valid?

When the conclusion NECESSARILY follows from the premises.

What makes an argument sound?

Terms are clear, propositions are true, and the argument is valid.

What are the 3 ways to defeat an argument?

Find unclear terms, false premises, invalid argument.

What is the definition of truth?

That which corresponds with reality.

What is the three-step process leading to certainty?

Observation (sensation), induction, deduction.

What is the difference between Inductive reasoning and Deductive reasoning?

Inductive reasoning = particular to universal; Deductive reasoning = universal to particular.

What is a Red Herring fallacy?

Distraction from the central argument.

What is a Hasty Generalisation fallacy?

Coming to a conclusion based on too small or poor a sample.

What is Equivocation fallacy?

Using one term multiple times with conflicting definitions.

What is Composition fallacy?

Assuming that what is true of a part is also true of the whole.

What is Special Pleading fallacy?

Arguing for an unjustified exception.

What is Ad Verecundiam fallacy?

Appeal to authority that is not a relevant expert.

What is Ad Populum fallacy?

Assuming that popular opinion is correct because it's the majority opinion.

What is Division fallacy?

Assuming that what is true of the whole is also true of the parts.

What is Arguing in a Circle fallacy?

Using a conclusion to justify a premise when you've already used that premise to justify the conclusion.

What is Non Sequitur fallacy?

Conclusion doesn't NECESSARILY follow from the premises.

What is Straw Man fallacy?

Making a weaker version of the argument in order to defeat it.

What is Genetic Fallacy?

Condemning an argument based on its origin.

What is Black and White Fallacy?

Arguing there are only two options when in fact there are more.

What is Abductive reasoning?

A form of reasoning that involves forming a conclusion based on the best available evidence.