Interface theory (Hoffman, Singh & Prakesh, 2015) is the hypothesis that inferential, representational theories of perception entail that fitness, not truth, dictates the evolution of perceptual systems. They show, with simulations, that ‘veridical’ perceptual mappings (ones that preserve at least some of the structure of the world) are routinely out-competed by ‘non-veridical’ interfaces (ones that make no attempt to preserve that structure). They therefore take particular aim at the direct perception, ecological approach to perception (Gibson, 1966, 1979; Turvey, Shaw Reed & Mace, 1981) and work to show that such a system, even if technically an option, would never be selected for by evolution.. This commentary defends the ecological approach from this novel attack by showing that a) Gibson does not make the mistakes he is accused of and, more substantively b) that the ecological hypothesis is so different in kind to the inferential, representational view of perception that it simply falls outside the scope of interface theory’s critiques. The heart of this defence is identifying the profoundly different ontologies (assumptions about the nature of the world to be perceived) underlying inferential and ecological approaches, and examining the consequences of these ontologies (including key problems for the inferential ontology that interface theory makes clear). Interface theory is a strong, clear formalisation of the inferential ontology, but it has no fatal implications for the ecological approach.