Limitations on an Inclusive Definition of Ecosystem-Human Health

Ethics and the Environment, 5(2):153—161 ISSN: 1085-6633 Copyright © 2000 Elsevier Science Inc. All rights of reproduction in any form reserved. David Castle Limitations on an Inclusive Definition of EcosystemHuman Health INTRODUCTION The ecology movement has been effective in focusing our attention on humanity's antipathy toward nature and the risks associated with that antipathy . Evidence of the effects of human-caused environmental destruction performed in the march of progress has long been recognized, but it has been realized only recently that degraded environments can reciprocate and impose severe if not final limits on human pursuits. Ecologists and philosophers who have foreseen our environmental midnight have attempted to reformulate contemporary society so that humanity and nature can work in concert, not in opposition. In this respect, the ecological movement has sponsored various forms of ecocentrism, all of which are distinguished by their attempt to integrate the norms underlying ecosystem health and human health. Despite the fact that significant aspects of the ecocentrist platform have been called into question (Steverson 1994), the prospect of their integration still has appeal. An integrated definition would imply that concern for human and natural welfare could be coextensive and that right action would simultaneously benefit humans and nature. Ostensibly, an inclusive definition of ecosystem-human health must satisfy two basic criteria. It must: 1. Articulate the relationship between human health and ecosystem health. 2. Provide a set of norms that are consistent for human health and ecosystem health. I argue that an analysis of the basic principles underlying ecosystem health and human health enable us to answer (1), but that it is not presently possible to answer (2) Direct all correspondence to: David Castle, Department of Philosophy, University of Guelph, Guelph, ON N1G 2W1, Canada; Phone: (519) 824-4120; E-mail: dcastle@open.uoguelph.ca 153 154 ETHICS AND THE ENVIRONMENT Vol. 5, No. 2, 2000 in a way that would make for a truly inclusive definition. Here is a brief sketch of my argument: The concept of ecosystem health is based on the science of ecology. Ecosystem health requires ecology to describe accurately the well-functioning of ecosystems; when it does, two basic kinds of norms are derived. On the one hand, we can describe the well-functioning of nature in itself. On the other, natural processes have consequences for our health—they are norms for us. Although norms of nature for us are ultimately predicated on bionorms, not all bionorms entail consequences for us. Accordingly , the relevant interactions required by the second criterion of an inclusive definition of ecosystem-human health are those that are identified by a limited set of ecosystem states that have consequences for us. In other words, ecosystem health in itself, as described by the bionorms, is not wholly relevant to the inclusive definition. Turning to the second criterion, I argue that because important differences exist in the way that ecosystem health and human health are characterized and measured, a consistent set of health norms required by the inclusive definition cannot be acquired. Instead, the nature of the relationship between ecosystem and human health indicates that an inclusive definition of ecosystem-human health is a stepped process of understanding the relevant interactions between humans and ecosystems, assessing the relevant bionorms, and determining their downstream consequences for us. I conclude that an inclusive definition of ecosystem-human health cannot contain a single set of norms but instead must rely on the analysis of the interactions between humans and ecosystems. THE CONCEPTUAL UNDERPINNINGS OF ECOSYSTEM HEALTH The modern science of ecology bears little resemblance to its intellectual progenitor — nineteenth-century natural history. Natural history has long been regarded as nonscientific because it is fundamentally descriptive and generally does not concern itself with causal explanations. Contemporary ecology, by contrast, provides causal explanations for the "processes influencing the distribution and abundance of organisms, the interactions among organisms, and the interactions between organisms and the transformation and flux of energy and matter" (Collins 1986). Since the 1920s, ecology has increasingly used mathematical modeling techniques and computer simulations (Kingsland 1995). The use of mathematical models is evident in many of the most prominent theories in ecology, such as Lotka and Volterra's...