The criterion which we use to test the genuineness of apparent statements of fact is the criterion of verifyability. We say that a... sentence is factually significant to any given person, if, and only if, he knows how to verify the proposition which it purports to express--that is, if he knows what observations would lead him, under certain conditions, to accept the proposition as true, or reject it as being false.... To make our position clearer, we may formulate it in another way. Let us call a proposition which records an actual or possible observation an experiential proposition. Then we may say that it is the mark of a genuine factual proposition, not that it should be equivalent to an experiential proposition, or any finite number of experiential propositions, but simply that some experiential propositions can be deduced from it in conjunction with certain other premises without being deducible from those other premises alone.LESSATTRIBUTION DETAIL »