Arthur Allen Leff

Who was Arthur Allen Leff?

Arthur Allen Leff was a professor of law at Yale Law School who is best known for a series of articles examining whether there is such a thing as a normative law or morality. Leff answers this question in the negative and follows the consequences to their logical conclusions.

Leff's first major work Economic Analysis of the Law: Some Realism About Nominalism is putatively a book review of Richard Posner's Economic Analysis of the Law. In actuality it is a critique of the use of any single methodology to provide normative rules for law and morality. The article is still, today, the main critique of Posner's work and economic analysis generally and is usually read in graduate seminars on Economic Analysis. Leff makes two fundamental proposition in SRAN: that all models are only very limited views of the real world. When Posner views the world through the economic model much more is hidden than is revealed; there is no system of logic for preferring one model over another unless an axiom is inserted early on into that system of logic. Leff notes that the opening of Posner's work does just that—inserts a proposition that rational economic behavior is to be preferred to other behavior.