Few energy issues in recent decades have proven as contentious as shale gas. Supporters and opponents often speak in such strikingly divergent terms that they seem to be describing different activities. Typically, supporters point to the economic and security impacts of shale gas, and minimize the adverse environmental and social effects. Opponents often point to negative environmental and social impacts, and downplay the economic and security effects. This chapter, from Shale Gas and the Future of Energy: Law and Policy for Sustainability (Edward Elgar 2016), explains sustainable development as an essential framework for providing a more complete understanding of whether shale gas contributes to overall human well-being. Key questions are whether shale gas development is sustainable and, if not, whether law and policy can actually make shale gas development sustainable. As this chapter also explains, it is not enough to make some progress toward sustainability. Key further questions are whether shale gas can help accelerate the transition to sustainability and, if so, how. These are the questions this book attempts to answer.