 On the other hand, the development of formal logic has been closely bound up with providing a clear language for presenting (and evaluating) deductive mathematical reasoning. Indeed, as John Burgess argues in his (1992), modern classical logic largely developed as a basis for mathematical reasoning, especially proof. The increase in rigor within mathematics during the 19th Century is properly viewed as a cause, not an effect, of the logical revolution set off by Frege’s work. Logic, in Burgess’s view, is descriptive: its goal is to construct mathematical models of reasoning. Classical logic constitutes an idealized description of classical mathematical proof.