Is complexity primarily an epistemological or an ontological phenomenon? Is there even any coherence at all in suggesting the latter ontological variety? Two of the twentieth century's greatest minds did approach this philosophical chestnut — Friedrich von Hayek and Herbert Simon.¹ Hayek and Simon share a key philosophical presupposition: that is, mind is constrained in its computational capacity to detect, harvest, and assimilate ("crunch" or process) data — data generated by the infinitely fine-grained and perpetually dynamic characteristic of experience in complex social environments.² To ameliorate this state of affairs, Hayek and Simon proffer an adaptive externalist theory of mind to spread the cognitive burden. For Hayek the social and artifactual world functions as a kind of distributed "extra-neural" memory store manifest as dynamic traditions, custom and practice — the sine qua non of acting, thinking, and communicating. For Simon, the "inner" world (i.e. the mind) has a homeostatic interface (a system that regulates its internal environment towards equilibrium), with the "outer" world modulated through the artifactual environment, most notably social institutions that give conceptual outline to thought and determine action. Both Hayek and Simon rejected the pernicious fiction of the unvarnished Cartesian reasoner manifest in the derivative guises of , on the one hand, central planning-type rationalism and, on the other hand, homo economicus so favored by orthodox economics.