A scientific field is not exhausted by the statements it contains; it persists through the relations that make those statements perceptible, comparable, memorable and actionable. Lewin’s field theory provides the initial displacement from isolated entities to dynamic configurations, insisting that behaviour becomes intelligible only within a total situation composed by person and environment. Barker gives this relational field a more concrete environmental form through the behaviour setting, where activities, places, temporalities and rules cohere into relatively stable arrangements that organise action. Gibson radicalises the environmental premise by defining surroundings through affordances: what matters is not merely what an environment is, but what it allows a situated actor to do.