validity

The term validity in logic (also logical validity) is largely synonymous with logical truth. However, the term is used in different contexts. Validity is a property of formulae, statements and arguments. A logically valid argument is one where the conclusion follows from the premises. An invalid argument is where the conclusion does not follow from the premises. A deductive argument may be valid but not sound. In other words, validity is a necessary condition for truth of a deductive syllogism but is not a sufficient condition.