For many scholars (see Smyth, 1995; Tilbury, 1995; Fien & Tilbury, 2002; Hopkins & McKeown, 2002) the emergence of the discourse of education for sustainable development (ESD) over the past 15 or so years is viewed as a progressive transition in the field, along similar lines to the positive portrayal of prior historical transitions from nature study to conservation education to environmental education (Stevenson, 1987). In this article, the author examines Smyth's (1995) and Bonnett's (2002) different positions on the potential for clarifying the ambiguities and contradictions of the concept of sustainable development, before focusing on Smyth's two claims. Central to both this issue of clarifying meanings of sustainable development and Smyth's second claim is the polarization of viewpoints on the human-environment connection which, drawing in part on Bonnett's different philosophical perspective, in which the author contends that it is limiting. Furthermore, in looking ahead to address the policy-practice tensions in environmental education and ESD, the author argues for contextualizing policy discourses by engaging educators in their co-construction.