Herman Daly, one of the founders of ecological economics, died on the 28th of October 2022 at the age of 84. His work questioning the pursuit of economic growth and articulating the alternative of a steady-state economy, has been foundational to sustainability science. Daly observed that mainstream economics completely omits the natural world and in reality, the economy is not an isolated system, but a subsystem of the biosphere. All of the resources used by the economy come from the environment, and all of the wastes produced by it return to the environment. Hence, economic activity can be analysed not only in terms of flows of money, but also in terms of flows of biophysical resources and social outcomes. Moreover, the finitude of the biosphere implies that there are limits to how large the physical economy within it can grow. Daly argued that we have in fact moved from an “empty world” to a “full world”. In this end of year episode we are paying tribute to Herman Daly. Alexandra Köves talks to Dan O'Neill, the President of the European Society for Ecological Economics in an episode that covers not just an incredibly rich life's work but most of the basic concepts of ecological economics. Edited by Aidan Knox.