This paper discusses the conceptual foundations for "Education for Sustainable Patterns of Living," the mission of the Center for Ecoliteracy in California. It offers an operational definition of ecological sustainability, and proposes study of living systems as a framework for understanding ecology. It considers key concepts for understanding living systems and their implications for educators. The paper addresses experiences that foster emotional connections with nature within a pedagogy for education for sustainable living. This paper is paired with Michael Stone's paper in this issue, "Rethinking School Lunch," which discusses practical applications of this conceptual grounding.