Complexity has recently risen to prominence in ecology as part of a broader interest that suggests its status is something more than just a scientific theory or property of reality. It may be helpful to consider complexity, and related terms such as “self-organization,” as recent metaphors deployed to advance knowledge on fundamental questions in ecology, including the relationship between parts and wholes, and between order and disorder. Though not commonly viewed as such, metaphors are an indispensable component of science, and should not be appraised as true or false, but rather in terms of how they help or hinder knowledge. By understanding metaphor as a necessary ally and not a threat to ecological knowledge, we may enrich our contextual understanding of complexity while continuing to invoke it in useful ways. The special section introduced by this article features essays by two prominent experts in ecology, complexity, and metaphor: science studies scholar Evelyn Fox Keller and theoretical ecologist Simon Levin.