Is income inequality more of a blemish or a failing organ in our economy? Both metaphors capture something about wealth disparities, but only failing organ seems to emphasize the fact that our economy is a complex system where activity in one region may lead to a cascade of problems in other parts of the system. In the present study, we introduce a novel method for classifying such “systemic” metaphors, which reveals that people can reliably identify the extent to which a metaphor highlights the complex causal structure of a target domain. In a second experiment, we asked whether exposing people to more systemic metaphors would induce a systems thinking mindset and influence reasoning on a seemingly unrelated task. We found that participants who were primed with systemic metaphors scored higher on subsequent tasks that measured relational and holistic thinking, supporting the view that these metaphors can promote systems thinking.