MATSEC IM Philosophy cheat sheet

Argument anatomy: premises are the reasons offered, the conclusion is what they are meant to support; indicator words such as 'because', 'since', 'given that' mark premises, while 'therefore', 'so', 'hence', 'it follows that' mark conclusions.

Validity is a structural property: an argument is valid if and only if it is impossible for all premises to be true while the conclusion is false. Soundness = validity plus all premises actually true, so a sound argument always has a true conclusion.

Deductive vs inductive: deduction aims at conclusions entailed by the premises (validity/invalidity applies); induction aims at conclusions made probable (assessed as strong or weak, cogent or uncogent).

Common formal fallacies: affirming the consequent (P→Q, Q, therefore P) and denying the antecedent (P→Q, not-P, therefore not-Q) are both invalid; modus ponens and modus tollens are valid.

Informal fallacies to distinguish: ad hominem (attacking the person), straw man (misrepresenting an opponent's position), false dilemma (presenting two options when more exist), begging the question (assuming the conclusion among the premises), post hoc ergo propter hoc (inferring causation from succession).

Necessary vs sufficient conditions: A is sufficient for B when A guarantees B; A is necessary for B when B cannot occur without A. Confusing the two underlies many errors in philosophical argument.

Counterexample method: to show a deductive argument invalid, describe a possible situation in which the premises are true and the conclusion false; to attack a universal claim, produce a single counterexample.

Conceptual analysis: give necessary and sufficient conditions for a concept, then test with imagined cases; a counterexample forces either revision of the conditions or rejection of the proposed analysis.

Plato's theory of Forms: particular sensible things are imperfect copies participating in eternal, non-physical Forms; the Form of the Good is the highest principle, and knowledge (episteme) contrasts with mere opinion (doxa).

Aristotle's four causes - material, efficient, formal, final - and his claim that the human good (eudaimonia) is activity of the soul in accordance with virtue, with virtues as habits lying between extremes (the doctrine of the mean).

Descartes' method of doubt: senses, dreams and an evil demon are doubted until the cogito ('I think, therefore I am') supplies an indubitable foundation; mind–body dualism follows from the claim that mind and body are distinct substances.

Hume's fork: relations of ideas (a priori, certain, e.g. mathematics) versus matters of fact (a posteriori, probable); causal necessity is not observed but projected by custom, and the is–ought gap blocks deriving values from facts alone.

Kant's Copernican turn: synthetic a priori judgements are possible because the mind imposes forms of intuition (space, time) and categories (e.g. causality) on experience; the phenomenal/noumenal distinction limits knowledge to appearances.

Utilitarianism: Bentham's hedonic calculus and Mill's greatest happiness principle assess acts by consequences; Mill distinguishes higher and lower pleasures and offers the harm principle for limiting coercion.

Kantian ethics: the categorical imperative has a universal-law formulation (act only on maxims you could will as universal law) and a humanity formulation (treat persons as ends, never merely as means); moral worth lies in duty, not inclination.

Virtue ethics (Aristotle, MacIntyre): the central question is 'what kind of person should I be?'; eudaimonia, phronesis (practical wisdom) and habituation of character traits replace rule- or consequence-based assessment.

Knowledge as justified true belief (Plato's Theaetetus, Gettier's 1963 counterexamples): JTB is necessary but arguably not sufficient; Gettier cases involve justified true belief that is true by luck, prompting added conditions such as no false lemmas or reliabilism.

Rationalism vs empiricism: rationalists (Descartes, Leibniz) hold some knowledge is innate or independent of experience; empiricists (Locke, Berkeley, Hume) hold the mind begins as a tabula rasa and all ideas derive from experience.

The problem of induction (Hume): no non-circular justification exists for inferring future regularities from past ones; Popper's falsificationism replaces confirmation with conjecture and attempted refutation, while Kuhn describes paradigm shifts rather than cumulative progress.

Mind–body positions: substance dualism (two kinds of substance), property dualism (one substance, two kinds of property), physicalism/identity theory (mental states are brain states), and functionalism (mental states are defined by causal role, hence multiply realisable).

Free will: hard determinism denies free will; compatibilism (Hume, Frankfurt) redefines freedom as acting on one's own desires without external constraint; libertarianism (e.g. agent causation) posits genuinely undetermined choices.

Metaethics distinctions: cognitivism holds moral statements express beliefs and can be true or false; non-cognitivism (emotivism, prescriptivism) holds they express attitudes; moral realism vs anti-realism concerns whether moral facts exist independently of us.

Political philosophy: Hobbes' state of nature and social contract, Locke's natural rights and consent, Rousseau's general will, and Rawls' veil of ignorance yielding the two principles of justice (equal basic liberties; the difference principle).

Philosophy of religion: the ontological argument (Anselm, Descartes - existence derived from the concept of a greatest being), the cosmological argument (Aquinas, Leibniz - contingency and sufficient reason), the teleological argument (Paley, fine-tuning), and the problem of evil as the main counter, with Plantinga's free-will defence among responses.

Essay structure that scores: state the thesis, define key terms precisely, present the argument with explicit premises, raise the strongest objection, respond, then conclude with the balance of reasons - not merely a list of philosophers' views.

When evaluating a theory, apply three tests: does it capture the relevant intuitions (descriptive adequacy)? does it explain the phenomenon better than rivals? does it avoid counterexamples and internal inconsistency?

Use thought experiments by name and function: the trolley problem (consequentialist vs deontological intuitions), the experience machine (hedonism), the ship of Theseus (identity), the brain in a vat (scepticism), Mary's room (physicalism).

Precision traps: 'valid' does not mean 'true'; 'true' does not mean 'justified'; 'moral' does not mean 'legal' or 'customary'; 'subjective' does not mean 'arbitrary'. Misusing these terms is the most common mark loss.

Quotation and attribution: attribute claims to the correct thinker (e.g. the categorical imperative to Kant, the harm principle to Mill, the cogito to Descartes) and distinguish an author's stated view from a later interpretation of it.

Distinguish descriptive from normative claims: a description of what people do never by itself establishes what they ought to do; identify any slide between the two as a gap in the argument.

Define contested terms operationally: 'freedom', 'justice', 'knowledge' and 'good' shift meaning across theories, so state which sense you are using before arguing, and keep it consistent throughout the answer.

Concluding judgements must be argued, not asserted: state which position survives the strongest objection and why, acknowledging the residual cost or unresolved difficulty of that position.