Abstract

Human beings are a marvel of evolved complexity. When we try to enhance poorly-understood complex evolved systems, our interventions often fail or backfire. It can appear as if there is a “wisdom of nature” which we ignore at our peril. A recognition of this reality can manifest as a vaguely normative intuition, to the effect that it is “hubristic” to try to improve on nature, or that biomedical therapy is ok while enhancement is morally suspect. We suggest that one root of these moral intuitions may be fundamentally prudential rather than ethical. More importantly, we develop a practical heuristic, the “evolutionary optimality challenge”, for evaluating the plausibility that specific candidate biomedical interventions would be safe and effective. This heuristic recognizes the grain of truth contained in “nature knows best” attitudes while providing criteria for identifying the special cases where it may be feasible, with present or near-future technology, to enhance human nature.