First-year courses · Humanities

Critical thinking and intro philosophy

Critical thinking and philosophy flashcards: arguments, validity, soundness, deduction and induction, common fallacies, major ethical theories and epistemology.

42 cards5 topicsAbout 15 minutes a roundTypical first-year Critical Thinking or Introduction to Philosophy

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About this deck

This deck covers the toolkit of a first-year critical thinking or introductory philosophy course. You will learn how to identify the parts of an argument, judge deductive arguments for validity and soundness, assess inductive reasoning, spot common fallacies, and compare the main ethical theories. A final group of cards introduces epistemology, the study of knowledge and justified belief.

Nothing beyond careful reading is required, but precision matters. In philosophy, words like valid, sound, true and strong have specific meanings that differ from everyday use. An argument can be valid with false premises, and a true conclusion can come from a bad argument. Learn those distinctions first; most exam questions test them.

Practise on real material. Take a newspaper opinion piece or a social media thread, rewrite the main argument as numbered premises and a conclusion, and then ask whether the conclusion follows and whether each premise is true. When you name a fallacy, explain in one sentence why the reasoning fails rather than just attaching a label.

Common mistakes: calling any argument you disagree with a fallacy; confusing a valid form like modus tollens with the invalid form of denying the antecedent; and summarizing ethical theories too loosely. Utilitarianism is about maximizing overall well-being, not simply doing what most people want, and Kant's ethics is about acting on principles you could will as universal laws, not following rules for their own sake.

Before you start: None.

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Cover the definitions with a sheet of paper and test yourself, or use the study modes above.

Argument basics

Argument: A set of statements in which some (the premises) are offered as reasons to accept another (the conclusion).Example: All mammals breathe air; whales are mammals; so whales breathe air.
Premise: A statement offered as a reason or evidence in support of a conclusion.Example: 'Whales are mammals' in the whale example.
Conclusion: The claim an argument is trying to establish, supported by the reasons given.Example: 'So whales breathe air.'
Indicator words: Words that signal the role of a statement in an argument, such as 'because' for reasons and 'therefore' for the main claim.Example: Since, given that, thus, hence, it follows that.
Principle of charity: Interpreting an opponent's argument in its strongest reasonable form before criticizing it.Example: Filling in an obvious unstated premise instead of attacking a weaker version.
Burden of proof: The obligation on the person making a claim to provide support for it.Example: Someone claiming a new supplement cures colds should supply evidence.
Necessary condition: Something that must be present for another thing to occur, though it may not be enough on its own.Example: Oxygen is required for fire, but oxygen alone does not start a fire.
Sufficient condition: Something whose presence guarantees that another thing occurs.Example: Being a square guarantees being a rectangle.

Deduction and induction

Deductive argument: Argument intended to guarantee its conclusion: if the premises are true, the conclusion cannot be false.Example: All residents of Alberta live in Canada; Priya lives in Alberta; so Priya lives in Canada.
Validity: Property of an argument whose form makes it impossible for the premises to be true and the conclusion false.Example: All cats are fish; all fish fly; so all cats fly. Bad premises, correct form.
Soundness: Property of an argument that has a correct deductive form and all true premises, so its conclusion must be true.Example: The Alberta and Canada example, given true premises.
Inductive argument: Argument whose premises make its conclusion probable rather than certain, often by generalizing from observed cases.Example: Every January in Winnipeg has been cold so far; next January will likely be cold.
Inductive strength: Degree to which premises, if true, make a conclusion likely; a strong argument with true premises is called cogent.Example: A large random sample gives more support than three anecdotes.
Abductive reasoning: Inference to the best explanation: choosing the hypothesis that best accounts for the evidence.Example: Wet streets and people with umbrellas suggest it rained.
Modus ponens: Valid form: If P then Q; P; therefore Q.Example: If it snows, school closes; it snowed; so school closes.
Modus tollens: Valid form: If P then Q; not Q; therefore not P.Example: If it snowed, the roads are white; the roads are not white; so it did not snow.
Counterexample: A case where the premises of an argument form are true but the conclusion is false, which shows that form is invalid.Example: Penguins are a counterexample to the claim that all birds fly.

Fallacies

Affirming the consequent: Invalid form: If P then Q; Q; therefore P.Example: If it rained the grass is wet; the grass is wet; so it rained. Sprinklers could explain it.
Denying the antecedent: Invalid form: If P then Q; not P; therefore not Q.Example: If you study you will pass; you did not study; so you will fail.
Ad hominem: Attacking the person making an argument instead of the argument itself.Example: Ignoring a climate study because the author drives a truck.
Straw man: Misrepresenting an opponent's position as weaker or more extreme so it is easier to attack.Example: 'You want bike lanes, so you want to ban cars.'
False dilemma: Presenting only two options as if no others exist.Example: 'Either we cut all arts funding or the budget collapses.'
Slippery slope: Claiming without adequate support that one step will lead inevitably to a chain of extreme consequences.Example: 'If we allow late assignments once, soon no one will submit anything.'
Begging the question: Assuming in the premises the very conclusion that is supposed to be proved; also called circular reasoning.Example: 'This source is trustworthy because it says it is trustworthy.'
Appeal to inappropriate authority: Relying on someone's endorsement on a topic outside their expertise.Example: A hockey star's view on vaccine safety.
Appeal to popularity: Arguing that a claim is true or good because many people believe or do it.Example: 'Millions use this diet, so it must work.'
Hasty generalization: Drawing a broad conclusion from too few or unrepresentative cases.Example: Meeting two rude drivers from a city and concluding everyone there is rude.
Post hoc ergo propter hoc: Assuming that because one event followed another, the first caused the second.Example: 'I wore my lucky socks and we won, so the socks caused the win.'
Red herring: Introducing an irrelevant topic to divert attention from the issue being discussed.Example: Answering a question about tuition increases by talking about sports teams.
Equivocation: Shifting between two meanings of the same word within an argument.Example: 'A feather is light; what is light cannot be dark; so a feather cannot be dark.'

Ethics

Utilitarianism: Ethical theory, associated with Bentham and Mill, holding that the right action produces the greatest overall well-being for everyone affected.Example: Choosing a public health policy that prevents the most suffering overall.
Deontology: Ethical theory holding that some actions are right or wrong in themselves, based on duties and rules, regardless of consequences.Example: Refusing to lie even when a lie would produce better results.
Categorical imperative: Kant's supreme moral principle: act only on maxims you could will to be universal laws, and treat humanity never merely as a means.Example: Making a false promise fails because universal false promising would destroy trust.
Virtue ethics: Approach, rooted in Aristotle, that focuses on developing good character traits such as courage, honesty and practical wisdom.Example: Asking 'What would a fair and honest person do here?'
Social contract theory: View that moral and political rules are justified because rational people would agree to them for mutual benefit.Example: Hobbes, Locke, Rousseau and Rawls each offered versions.
Ethical relativism: View that moral rightness depends on the beliefs or practices of a culture or individual rather than on universal standards.Example: Critics ask how moral reformers could then ever be right.

Knowledge

Epistemology: Branch of philosophy that studies the nature, sources and limits of knowledge and justified belief.Example: Asking how we know the sun will rise tomorrow.
Justified true belief: Traditional analysis stating that someone knows a claim when they believe it, it is true and they have good reason for it.Example: Believing your exam is Friday because the syllabus says so, and it is.
Gettier problem: Cases where someone has a true belief with good reasons yet seems not to know, because the truth was reached by luck.Example: A stopped clock that happens to show the right time.
Empiricism: View that knowledge comes mainly from sensory experience; associated with Locke, Berkeley and Hume.Example: Learning that ice melts by observing it.
Rationalism: View that reason can provide some knowledge independent of experience; associated with Descartes, Spinoza and Leibniz.Example: Knowing that 7 + 5 = 12 without needing to count objects.
Philosophical skepticism: Position that questions whether we can have knowledge at all, or knowledge in a particular area.Example: Descartes asked how he could know he was not dreaming.