In vice epistemology, bad epistemic outcomes, such as maintaining false beliefs, are interpreted as indicators of blameworthy irrationality. Conversely, a growing trend in philosophical psychology advocates for environmentalist explanations, suggesting these outcomes emerge because rational cognitive processes of faultless individuals falter due to polluted environmental inputs. Building on concrete examples, I first offer a systematic analysis of the relative explanatory merits of that environmentalist project. I then use this analysis to advance the rationality debate, which has recently been identified as (...) stagnating due to an observational equivalence between environmentalist and vice accounts. Although the conceptual imprecision of vice epistemology has frequently been critiqued, the framework developed here reveals that environmentalism is (also) unable to meet various theoretical desiderata. I show why this is so and argue that, to make progress, environmentalism needs a more substantive conception of epistemic rationality. To this end, I propose that a closer engagement with questions of cognitive agency – how rational creatures can “make up” their minds about what to believe – could enable the necessary progress. (shrink)