Box 1.

Ontological and epistemological approaches to systems thinking

Systems thinking falls into two main categories regarding how the term ‘system’ is understood and used, which has important implications for a leverage points approach to sustainability. This ontological versus epistemological divide relates to whether systems are viewed as real-world phenomena that can be objectively studied [e.g. Liu et al. “our planet is a single system comprising complex interactions between humans and nature” (2015, p. 1258832-1], or as an epistemological approach to addressing particular issues of interest or concern (e.g. Ison 2010). Unlike Meadows, we take a more epistemological approach to the notion of systems. That is, we view systems thinking as a lens through which sustainability issues can be addressed. As such, a ‘system’ is bounded and defined by the subjective interests and pre-analytic assumptions of the researcher, with all the potential problems this entails. This epistemological approach means that particular importance must be placed on how, and why, the researcher chooses to delineate a system and what implications this has in the context of solution-oriented sustainability science. Following Ison (2008), we use the term ‘system of interest’ to acknowledge that systems are, in part, defined by the worldviews and concerns of researchers and other actors involved