An argument is a list of statements called premises given in support of a final statement called the conclusion. Consider, for example, the following argument. 1. Socrates is a person; 2. All persons are mortal; therefore, 3. Socrates is mortal. Statements (1) and (2) are this argument’s premises and statement (3), which “follows” from (1) and (2), is its conclusion. Two properties are relevant to evaluating arguments: validity and soundness. • Arguments are valid when it is the case that if their premises are true, then their conclusions must also be true. • Arguments are sound when it is the case that they are both valid and all of its premises are true.
