AbstractWhere some religious environmentalisms deploy traditional concepts according to the practical needs of cosmology, usul al-fiqh (jurisprudence) envisions an alternative practical strategy for Islamic environmental ethics. Jurisprudence governs religious adaptations according to guiding principles designed to conform practical reason to the ongoing discovery of divine will. This article shows how those principles can function as mechanisms for normative change, and reviews their diagnostic capacity for evaluating various uses of Islamic resources.