Critical Thinking

  1. Proposition
    A statement that expresses an idea that can either be true or false.
    Example: "The Earth orbits the Sun" is a proposition because it is a statement that can be verified as true or false.

  2. Premise indicator
    Words or phrases that signal the presence of a premise in an argument, such as "because," "since," or "for."
    Example: "Because all humans are mortal, and Socrates is a human, Socrates is mortal." ("Because" indicates the premise.)

  3. Inference
    The process of drawing a conclusion from premises or evidence.
    Example: If you observe that the sky is cloudy and the wind is strong, you might infer that it will rain soon.

  4. Deductive reasoning
    A type of reasoning where conclusions are derived from general premises, and the conclusion must be true if the premises are true.
    Example: All men are mortal. Socrates is a man. Therefore, Socrates is mortal.

  5. Invalid reasoning
    Reasoning where the conclusion does not logically follow from the premises, even if the premises are true.
    Example: All cats are animals. All dogs are animals. Therefore, all cats are dogs. (The conclusion doesn't follow from the premises.)

  6. Valid reasoning
    Reasoning where the conclusion logically follows from the premises, ensuring that if the premises are true, the conclusion must also be true.
    Example: All humans are mortal. Socrates is a human. Therefore, Socrates is mortal. (This reasoning is valid because the conclusion logically follows from the premises.)

  7. Inductive reasoning
    A type of reasoning that involves drawing general conclusions from specific examples or observations.
    Example: Every swan I have seen is white. Therefore, all swans are probably white.

  8. Cogent
    A property of an inductive argument that is strong and has true premises.
    Example: "Most dogs are friendly, and I've met ten friendly dogs." This is a cogent argument because the premises are true, and the argument is strong.

  9. Sound
    A property of a deductive argument where the argument is valid and all its premises are true.
    Example: All birds can fly. A sparrow is a bird. Therefore, a sparrow can fly. (This argument is valid, but not sound, as the first premise is false.)

  10. Denying the antecedent
    A logical fallacy that occurs when one assumes that if "if A then B" is true, then "not A" means "not B."
    Example: If it is raining, then the ground is wet. It is not raining. Therefore, the ground is not wet. (This is an invalid inference.)

  11. Affirming the consequent
    A logical fallacy that occurs when one assumes that if "if A then B" is true, then "B" implies "A."
    Example: If it is raining, then the ground is wet. The ground is wet. Therefore, it is raining. (This is a fallacy because there could be other reasons for the ground being wet.)

  12. The fallacy fallacy
    The mistake of assuming that just because an argument contains a fallacy, its conclusion must be false.
    Example: "He made a logical error in his argument, so his conclusion must be false." (This is a fallacy fallacy.)

  13. Context collapse
    The situation where different social contexts converge, causing a blending of expectations and norms, which can affect communication and behavior.
    Example: Posting a personal message on social media that is meant for friends but is viewed by coworkers, causing a misunderstanding.

  14. The principle of charity
    Interpreting someone's statements in the most rational way possible, assuming good intentions, and giving the benefit of the doubt by understanding their argument in its strongest, most logical form.
    Example: When someone says, "I think the economy is bad," interpreting their statement as a genuine concern about current economic conditions rather than assuming they are just complaining without reason.

  15. Confirmation bias
    The natural tendency to minimize or ignore evidence contrary to one's beliefs while seeking out and relying on evidence that supports one's beliefs.
    Example: A person who believes that all politicians are corrupt might only focus on news stories about corrupt politicians and ignore those about ethical politicians.

  16. Representativeness
    The tendency to apply a mental prototype from previous experience to interpret a new situation.
    Example: Meeting someone who wears glasses and assuming they are smart because you associate glasses with intelligence.

  17. Cogency
    A property of an inductive argument if it is strong and has true premises.
    Example: "Every dog I've met has been friendly, so all dogs must be friendly." This is cogent because the premises are true and the argument is strong, though not necessarily valid for all dogs.

  18. Availability
    The tendency to interpret a new situation using information readily available, without considering additional information that may affect the situation.
    Example: After hearing about a plane crash on the news, someone might think flying is more dangerous than it actually is, just because the event is memorable.

  19. Alief
    A type of belief or attitude that is often unconscious and automatic, which can influence behavior even if it conflicts with one's conscious beliefs.
    Example: A person who consciously believes in equality may feel nervous or uncomfortable when interacting with people from different backgrounds, even though they don't believe in inequality.

  20. Ad Hominem
    A fallacy where the argument attacks a person’s character rather than addressing the argument itself.
    Example: "You can't trust his opinion on climate change because he's not a scientist."

  21. Genetic Fallacy
    A fallacy that involves dismissing or validating an argument based on its origin or source rather than its merit.
    Example: "That idea is stupid because it came from an unreliable source."

  22. Straw Man
    A fallacy that misrepresents or oversimplifies an opponent's argument to make it easier to attack.
    Example: "You want to lower taxes? You must want to eliminate all government services!"

  23. Red Herring
    A fallacy that introduces an irrelevant topic to divert attention from the original issue.
    Example: "We shouldn't be worried about the environment. What about all the people losing their jobs because of the economic downturn?"

  24. Irrelevant Appeals
    Fallacies that use an appeal to irrelevant authority, emotion, or other factors to distract from the actual argument.
    Example: "My grandfather smoked 20 cigarettes a day and lived to be 90, so smoking can't be that bad for you."

  25. Equivocation
    A fallacy that uses an ambiguous term or word in different ways to mislead or confuse the argument.
    Example: "A feather is light. What is light cannot be dark. Therefore, a feather cannot be dark."

  26. Appeal to Ignorance
    A fallacy that argues that a lack of evidence against something proves it is true.
    Example: "No one has proven that aliens don't exist, so they must be real."

  27. Slippery Slope
    A fallacy that assumes a small action will lead to a series of negative consequences, without sufficient evidence.
    Example: "If we allow students to redo their homework, next they'll want to retake entire courses, and before we know it, they'll want to control the curriculum!"

  28. Texas Sharpshooter
    A fallacy where someone cherry-picks data or information to fit their argument, ignoring other contradictory evidence.
    Example: A person who shows only the best 5 years of investment returns and claims those returns are typical for their strategy.

  29. Post Hoc
    A fallacy where one assumes that because event A happened before event B, A caused B.
    Example: "I wore my lucky socks and then we won the game, so my socks must be lucky."

  30. Hasty Generalization
    A fallacy that involves making a broad generalization based on a small or unrepresentative sample.
    Example: "I met two people from Canada, and they were both really friendly. All Canadians must be friendly."

  31. Presumption
    A fallacy where one assumes something without proper evidence or argument.
    Example: "Since I didn't hear anything about the meeting being canceled, I assume it is still on."

  32. Conjoint vs. Independent Support
    The distinction between arguments that support each other and those that stand alone in providing separate evidence for a conclusion.
    Example: Conjoint: "He passed the exam because he studied hard and had prior knowledge." Independent: "He passed because he studied hard" (separate reasons for success).

  33. Argument Layers
    The structure or hierarchy of reasons and evidence that support or oppose a conclusion in an argument.
    Example: An argument about climate change may have layers, such as scientific data, expert testimony, and personal observations.

  34. Hidden Assumptions
    Unstated beliefs or premises that are necessary for an argument to work but are not explicitly acknowledged.
    Example: "All artists should be respected" assumes that respect is deserved simply by being an artist, without justifying why.