There is a Darwinian version of critical realism, but does it make sense? It goes something like this: There is a reality external to but inclusive of experience which has determined experience along evolutionary lines. Our entire understanding of that reality, which belongs to experience, having evolved according to maximal fitness is a reflection of it only in its aspect of fitness landscape and not as it is in itself. The shaping of experience is real, but relative to the whole of reality, the shaping process is unrepresentative or uninformative. Experience comprehends itself and its world only by way of distinctions historically determined by fitness and these distinctions bear no necessary relations to the distinctions intrinsic to reality. It seems that this both underestimates and overestimates the function of understanding. It underestimates it in that it does not take into account the ability of understanding to exceed its brief, to seize on the smallest anomalies and inconsistencies in order to forge a larger and deeper view of things than was imagined possible. For example tool use has a clearly role in maximising fitness, but it would be impossible to predict modern scientific instruments from the typical evolutionary use cases of primitive tools. On the other hand it overestimates understanding in maintaining realism, that of all the basic prejudices of understanding the one that should remain unquestioned is that which insists on an external and determinative reality with a distinct nature of its own.