Defining Nature for Policy and Practice

What counts as "nature" is increasingly central to public policies, investment decisions, and scientific assessments, yet the term is often left undefined or implicit. Because nature is a complex, value-laden concept, a universal definition is unlikely to serve all uses, creating problems for comparability and auditability of claims. When users document what counts as nature and disclose the basis for their claims, measurement becomes more comparable, and accountability improves. We present a framework that pairs a concise definition with its purpose, context, and boundary rules, and apply it to develop a definition of nature that can reveal how benefits, harms, and stewardship responsibilities are distributed across people and places. Definitions should be treated as public commitments: articulating both a definition and a replicable process for revision makes governance more transparent, auditable, and open to legitimate contest.