ABSTRACT
Philosophy.—Validation is a type of method used for justifying the statements of a science (→EPISTEMOLOGY). Validation in the formal sciences can be distinguished from validation in the empirical sciences. In the formal sciences, demonstration is the validity criterion: a proposition capable of being validated is a proposition capable of being demonstrated, that is, derivable in an axiomatic system (→LOGIC). In the empirical sciences, a proposition to be validated must be deducible from a general law (with initial conditions); in addition, it must be testable by means of an experimental test that does not presuppose its own truth (→EXPERIENCE, TRUTH). This type of validation is called hypotheticodeductive (→ REASONING AND RATIONALITY). A proposition can be confirmed or rejected on this basis. But as Karl Popper showed, it cannot, strictly speaking, be verified because a true consequence can follow from false premises. A proposition that cannot be validated in any manner has no informative content, even if in some cases it can be granted a heuristic value.
