Gibson’s ecological theory of perception displaces representation from the centre of perceptual explanation and replaces it with direct engagement between an organism and an information-rich environment. The concept of affordance is its most durable intervention: environments are perceived through the possibilities for action they offer relative to particular forms of embodiment and capability. An affordance is neither a subjective projection nor an intrinsic property of an object; it exists relationally between agent and environment. This changes method as much as ontology, directing analysis toward action possibilities, environmental information and situated perception rather than internal reconstruction alone. The wider theoretical force of Gibson’s work lies in making usability, access and capacity constitutive features of environments. His account bridges perceptual psychology with design, architecture, human–computer interaction and ecological thought, wherever the central question becomes not only what a thing is, but what configurations of action it enables.