According to several authors, our contemporary cultural landscape is characterized by an emergent, integrative cultural movement and worldview, which attempts to reconcile rational thought and science with a spiritual sense of awe for the cosmos. This rational "cosmic piety" may hold important potentials for sustainable development. This study aims to generate insight into this worldview by qualitatively exploring it in in-depth interviews with twenty "integrative" environmental leaders. The results demonstrate that these individuals tend to: share an evolutionary/developmental, spiritual-unitive perspective on the nature of reality (ontology), hold a positive view on human nature as characterized by a vast, though generally unrealized, potential (anthropology), emphasize an internalization of authority, as well as an integration of multiple modes of knowing (epistemology), and engage in their sustainability-work from a spiritual foundation (axiology). The results also show how these premises logically flow forth in an imaginary of a more sustainable society, or a "sustainable social imaginary" (societal vision) which tends to be 1) positive; 2) emancipatory; 3) inclusive of post-rational ways of working/knowing; and 4) integrative/synthetic. The article concludes that this social imaginary may serve the important task of public communication and large-scale mobilization for sustainable solutions to our pressing, planetary issues.