One of the most significant epistemological events in recent years is the growing importance of historical questions in the ongoing reconceptualization of the hard sciences. I believe it is not an exaggeration to say that in the last two or three decades, history has almost completely infiltrated physics, chemistry and biology. It is true that nineteenth century thermodynamics had already introduced an arrow of time into physics, and hence the idea of irreversible historical processes. It is also true that the theory of evolution had already shown that animals and plants were not embodiments of eternal essences but piecemeal historical constructions, slow accumulations of adaptive traits cemented together via reproductive isolation. However, the classical versions of these two theories incorporated a rather weak notion of history into their conceptual machinery: both thermodynamics and Darwinism admitted only one possible historical outcome, the reaching of thermal equilibrium or of the fittest design. In both cases, once this point was reached, historical processes ceased to count. For these theories, optimal design or optimal distribution of energy represented, in a sense, an end of history.