Why can a deductively valid argument have false premises?

In formal logic, a deductively valid argument can have false premises because validity is a property of an argument's form or structure, rather than the truth of its content.12

An argument is considered deductively valid if the conclusion follows from the premises with strict necessity. Specifically, an inference is valid if it is impossible for the premises to be true while the conclusion is false. This definition focuses entirely on the logical relationship between the statements: if the premises were true, the conclusion would have to be true.1345

Because validity depends only on this structural guarantee, it remains intact regardless of whether the premises are actually true or false in the real world. When an argument is both valid and possesses true premises, it is termed sound. However, logicians distinguish between these two concepts: the study of validity is concerned with whether the inference is logically correct, while the determination of the truth of the premises is a separate task often left to other disciplines or common observation.12