QCAA Philosophy & Reason flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Validity

A property of argument form: if the premises were true, the conclusion could not be false. Validity says nothing about whether the premises are actually true.

Soundness

An argument is sound when it is valid and all its premises are actually true. Soundness guarantees the truth of the conclusion.

Modus ponens

Valid form: if P then Q; P; therefore Q. Affirming the antecedent guarantees the consequent, so the conclusion follows necessarily from the premises.

Modus tollens

Valid form: if P then Q; not Q; therefore not P. Denying the consequent rules out the antecedent, making the inference deductively valid.

Affirming the consequent

Invalid form: if P then Q; Q; therefore P. The consequent can have other causes, so the inference from Q back to P does not hold.

Denying the antecedent

Invalid form: if P then Q; not P; therefore not Q. The consequent may still obtain through a different sufficient condition.

Disjunctive syllogism

Valid form: P or Q; not P; therefore Q. Once one disjunct is eliminated, the remaining disjunct must be true.

Counterexample

A single case that shows a universal claim is false. One genuine instance of an A that is not B refutes the claim that all A are B.

Inductive strength

A graded property of support: strong inductive arguments make the conclusion highly probable given the premises, but never guarantee it.

Thesis statement

A single contestable sentence stating the essay's central claim, plus the criterion by which that claim will be assessed in the body.

Standard form

Numbered premises followed by the conclusion, with any unstated assumptions made explicit and flagged, so the argument's structure can be inspected.

Linked premises

Premises that support a conclusion jointly: together they provide the reason, but neither supports the conclusion on its own.

Convergent premises

Independent premises that each provide separate support for the same conclusion, so removing one leaves the other's support intact.

Principle of charity

Interpreting an opponent's argument in its strongest, most plausible form before criticising it, so the critique targets the best version of the view.

Empirical premise

A premise about how the world actually is, assessed by evidence, observation, or data rather than by conceptual analysis alone.

Normative premise

A premise about what ought to be, or about value, assessed by examining principles and their implications rather than by empirical data alone.

Thought experiment

A described hypothetical case used to test whether a principle matches considered intuitions, especially at borderline or extreme cases.

Straw man

A fallacy in which an opponent's position is weakened or distorted before being attacked, so the rebuttal does not touch the real view.

Exposition versus justification

Exposition states what a philosopher claims and why; justification evaluates whether those reasons actually support the claim. Analytical essays need both.

Fallacy mechanism

The specific step at which an inference fails, such as treating a sufficient condition as necessary. Naming the mechanism is stronger than naming the fallacy.

Necessary condition

A condition that must be present for something to occur; without it the thing cannot happen, though it may not be sufficient on its own.

Sufficient condition

A condition whose presence guarantees the outcome, though the outcome may also be produced by other conditions.

Conceptual analysis

The method of proposing necessary and sufficient conditions for a concept, then testing them against borderline cases and counterexamples to refine the definition.

Is–ought gap

The claim that purely descriptive premises cannot by themselves entail a normative conclusion; deriving an ought requires at least one normative premise.

Descriptive claim

A claim about what is the case, which can in principle be checked against evidence, observation, or established fact.

Normative claim

A claim about what ought to be, what is valuable, or what is required, which cannot be settled by empirical evidence alone.

A priori knowledge

Knowledge justified independently of experience, such as logical or mathematical truths, derived by reasoning rather than observation.

A posteriori knowledge

Knowledge justified through experience, observation, or empirical evidence, such as findings about how the world actually is.

Explanatory power

A theoretical virtue: the capacity of a theory to account for a wide range of phenomena with few additional assumptions.

Parsimony

The theoretical virtue of simplicity: other things equal, prefer the theory that posits fewer entities or makes fewer independent assumptions.

Reflective equilibrium

A method of adjusting general principles and particular judgements until they cohere, using each to revise the other where they conflict.

Charitable reconstruction

Restating a position with its strongest supporting reasons and plausible unstated assumptions, then evaluating that version rather than a weaker one.