A number of prominent advocates of applying behavioral economics to the law make the claim that behavioral law and economics is simply a refinement of traditional law and economics. The key difference is that behavioral law and economics uses more realistic descriptions of human behavior as its foundation. This paper takes issue with that claim. We first demonstrate through a series of examples that the strongest adherents of behavioral law and economics take positions that can be seen as subversive of the fundamentals of the core rationality principles underlying traditional law and economics. Second, the assessment of welfare within behavioral economics differs sharply from the traditional economic paradigm used in law and economics.Nombr...