The environmental and interdisciplinary nature of environmental education presents extraordinary challenges to individuals' abilities as a field to clearly conceptualize, theorize and communicate findings about what they have learned about practice, research and theory in environmental learning (Disinger, 2001). Unfortunately, these factors also make it difficult for practitioners to identify research-based advice on what they know about the principles and practices of environmental learning, and for researchers and observers to understand what they agree and disagree about in this research. These problems contribute to what appears to be a lack of general understanding of an important point for environmental educators--that inquiry in environmental education has identified a body of warranted judgements about learners that is useful for guiding work with them. This is the case despite the need for substantial research into the experiences of learners, learning and teaching in environmental education (Rickinson, 2001). In this article, the author summarize these key recommendations and set out the case for the importance of developing a working epistemology to help individuals resolve the apparent contradiction between, on the one hand, the view that they do have adequate evidence to guide their work, and on the other, the view that they need much more research and inquiry regarding these matters.