Every sound deductive argument is valid, but a valid argument may be unsound.

### Why this is right The statement gives the required relationship between validity and soundness. Soundness includes validity as one of its conditions, but validity alone does not guarantee that the premises are true. ### The concept Validity asks whether the conclusion must follow if the premises are assumed true. Soundness adds a factual check: every premise must actually be true. For example, “All birds can fly; penguins are birds; therefore penguins can fly” has a valid form but a false premise, so it is unsound. The argument's valid form does not make its premise true. ### The other options - **False**: would wrongly deny that validity is required for soundness, or claim that every valid argument has true premises. ### Terms - **Deductive argument**: An argument that presents its premises as guaranteeing its conclusion. - **Validity**: Logical support that rules out true premises with a false conclusion. - **Soundness**: Validity combined with true premises. - **Unsound**: Not sound because the argument is invalid, has a false premise, or both. ### Remember Sound means valid plus true premises, so validity is necessary but not sufficient.