Many professionals regard the study of history as a waste of time. I can understand this sentiment where research proceeds rather automatically and largely without concern for possible social censure, but where societal forces directly complicate the agenda involved, there is reason for proceeding with a more open mind. Ignorance of the past invites reinventing the wheel; not only with respect to specific theories or models that were designed in some past era but never fully tested, but also to more general points of view that may extend beyond the immediate science of the question. Meanwhile, within most fields of knowledge there are constant attempts at reinvention; in many of these theory or research paradigms may become stale or stagnant. But just as often societal evolution may produce new agenda, including ones that require wholly new perspectives. The biodiversity movement of the past fifteen years is a good example of such forces in action. Human population pressures increasingly test the planet's ability to renew itself, a momentum that has caused conservationists and planners to move away from single-species and intra-national forms of management and toward larger-scale, interdisciplinary, understandings of the socio-natural processes at work.