Philosophical study of the nature and scope of logic .
Examples of questions raised in the philosophy of logic are: "In virtue of what features of reality are the laws of logic true?"; "How do we know the truths of logic?"; and "Could the laws of logic ever be falsified by experience?" The subject matter of logic has been variously characterized as the laws of thought , "the rules of right reasoning," "the principles of valid argumentation," "the use of certain words called logical constants," and "truths based solely on the meanings of the terms they contain."