Sustainability is a buzz word these days. It permeates many levels of human activity and is manifest on human, social, economic, and environmental dimensions. Yet, definitions are often unclear and poorly conceptualized. This text identifies two distinct perspectives for evaluating sustainability. The first is concerned with micro-level concerns related to the continuation of programs, policies, and other types of human action. The second takes a macro level perspective concerned with sustaining human, social, and economic development under consideration of protecting the environment. It is...