Final answer:
It is false that an argument with a tautology as one of its premises must be valid. The validity of an argument depends on whether the conclusion logically follows from the premises, not just on the truth of the premises.
Step-by-step explanation:
The question asks whether an argument with a tautology as one of its premises is necessarily valid. The statement that an argument with a tautological premise must be valid is false. A tautology is a statement that is true by necessity or by virtue of its logical form; however, the validity of an argument is determined by whether the conclusion logically follows from the premises, not merely by the truth of the premises.
To illustrate, let's consider a simple deductive inference in the form of a disjunctive syllogism: 'Either the cat is white or the cat is not white (tautology), the cat is white, therefore the animal is a cat.' While the premises are true (with the first being a tautology), the conclusion does not logically follow since the premise that the cat is white does not provide enough information to conclude that only a cat can be white.
Therefore, an argument can contain a tautological premise and still be invalid if the premises, tautological or not, do not adequately support the conclusion. Validity requires that if the premises are true, the conclusion must be inevitable, which may not be the case even with a tautological premise.