 In 1936, Rudolf Carnap switched the goal of scientific statements' "verification", clearly impossible, to the goal of simply their "confirmation".Meanwhile, similarly, ardent logical positivist A J Ayer identified two types of verification—"strong" versus "weak"—the strong being impossible, but the weak being attained when the statement's truth is "probable".In such mission, Carnap sought to apply probability theory to formalize inductive logic by discovering an algorithm that would reveal "degree of confirmation".