The wars and revolutions of the twentieth century left this specifically ‘modern’ picture of the world in tatters, and in many different fields – not least in architecture and the arts – it has long since been superseded.4 In philosophy, something more adequate to the changed situation than phenomenology, logical empiricism and structuralism was needed, but apart from existentialism, what we got were the irrationalism and relativism which are now unfortunately associated with the term ‘post-modern’. But ecology as a science, though it contributed to this new intellectual environment, is much more than a passing fashion.5 It arose from the study of open self-sustaining systems, such as ponds and forests, and their environments. The stability of the inter-relationships established within and between such systems cannot be explained by the type of linear or mechanical causality appropriate to classical chemistry or physics; we need to have recourse to the reciprocal causality of feedback loops explored by unorthodox pioneers like Gregory Bateson and the creators of chaos theory.6 It is an open question, however – though undoubtedly an extremely important one – whether ethics and religion have made the same transition to recognizably post-modern ways of conceiving the world as itself an ecological system, an all-encompassing organism of which human societies and their ways of giving meaning to the world are integral parts.7