In this talk, I will I argue that this resurgent enthusiasm for rationality is misplaced, for three reasons. First, I will suggest that recent empirical arguments in favor of human rationality rest on a fallacy of composition, implicitly but mistakenly assuming that evidence of rationality in some (carefully analyzed) aspects of cognition entails that the broader whole (i.e. the human mind in toto) is rational. In fact, establishing that some particular aspect of cognition is optimal (or perfect, or near optimal) is not tantamount to showing that the system is a whole is; current enthusiasm for optimality overlooks the possibility that the mind might be suboptimal even if some (or even many) of the components of cognition have been optimized. Second, I will argue that there is considerable empirical evidence (most well-known, but rarely given due attention in the neo-Rationalist literature) that militates against any strong claim of human cognitive perfection. Finally, I will argue that the assumption that evolution tends creatures towards rationality or “superlative adaptation” is itself theoretically suspect, and ought to be considerably tempered by recognition of what Stephen Jay Gould called “remnants of history”, or what might be termed evolutionary inertia.