Representational views of the mind traditionally face a skeptical challenge on perceptual knowledge: if our experience of the world is mediated by representations built upon perceptual inputs, how can we be certain that our representations are accurate and our perceptual apparatus reliable? J. J. Gibson's ecological approach provides an alternative framework, according to which direct perception of affordances does away with the need to posit internal mental representations as intermediary steps between perceptual input and behavioral output. Gibson accordingly spoke of his framework as providing “reasons for realism.” In this paper I suggest that, granting Gibson his reasons for perceptual realism, the Gibsonian framework motivates anti-realism when it comes to scientific theorizing and modeling. If scientists are Gibsonian perceivers, then it makes sense to take their use of models in indirect investigations of real-world phenomena not as representations of the phenomena, but rather as autonomous tools with their own affordances.