This dissertation analyzes the way in which leaders of certain Taiwanese Buddhist organizations associated with a strand of Buddhist modernism called "humanistic Buddhism" use discourse and rhetoric to make environmentalism meaningful to their members. It begins with an assessment of the field of religion and ecology, situating it in the context of secular environmental ethics. It identifies rhetoric and discourse as important but under acknowledged elements in literature on environmental ethics, both religious and secular, and relates this lack of attention to rhetoric to the presence of a problematic gap between environmental ethics theory and environmentalist practice. This dissertation develops a methodology of rhetorical analysis that seeks to assess how rhetoric contributes to alleviating this gap in religious environmentalism. In particular, this dissertation analyzes the development of environmentalism as a major element of humanistic Buddhist groups in Taiwan and seeks to show that a rhetorical analysis helps demonstrate how these organizations have sought to make environmentalism a meaningful subject of contemporary Buddhist religiosity. This dissertation will present an extended analysis of the concept of "spiritual environmentalism," a term developed and promoted by the late Ven. Shengyan (1930-2009), founder of the Taiwanese Buddhist organization Dharma Drum Mountain. Furthermore, this dissertation suggests that the rhetorical methodology proposed herein offers offers a direction for scholars to more effectively engage with religion and ecology in ways that address both descriptive/analytic approaches and constructive engagements with various forms of religious environmentalism.