Four Possible Combinations

Every argument lands in one of four boxes:

• Valid + true premises = sound — the logic works and the facts hold
• Valid + false premises = unsound — the logic works, the facts don't
• Invalid + true premises — correct facts, broken reasoning
• Invalid + false premises — nothing works at all

Only sound arguments earn your trust. The sneakiest box is valid plus false premises: the structure is so clean the conclusion feels inevitable, and the false foundation slips by unnoticed.