Abstract

This dissertation defends an epistemology that is simultaneously naturalistic---partaking of a consistently scientific worldview---and rationalistic---admitting of the existence of a priori justification. To attain such a naturalistic rationalism , we need to acknowledge that the unconscious structure of our inferential and intuition-producing mechanisms may be relevant to the justificatory status of our cognitions. Such an acknowledgement first requires admitting a limited version of epistemological externalism, which is defended by appeal to an 'analysis-by-imagined-reconstruction'. That is, we explore our norms of justification by imagining how we would re-design those norms ourselves, given our epistemic goals of diachronic reliability and dialectical robustness. These 'DR desiderata' motivate some internalist constraint on justification, to help us keep track of truths and allow us to manage our investigative disputes. But a thoroughgoingly internalist norm is of no use to us, since no agent with our limitations and psychological make-up could satisfy it. Moreover, an externalist loophole would be permissible in circumstances where the truth is stable and where agreement is guaranteed---precisely conditions that attain in many classic cases of a priori justified beliefs, such as in basic mathematical truths. The initial take on this externalist loophole proves to be slightly too broad, since obvious and unchangingly true statements like 'There have been dogs' fall under it as well. An appeal to conceptual truths to tighten that loophole is considered, but rejected as ultimately specious. Rather, in appealing to the computational structure of the underlying psychological mechanisms, we can see that some cognitions are fundamentally rational---produced by mechanisms that we could construe a cognitive engineer with our goals in mind producing just such a design. We have good scientific reason to expect that much---but nowhere near all---of our cognitive psychology does display such rational design, even though it was designed by nature's tinkerings. The resulting framework of NR is then applied to some extant debates philosophical intuitions, and it is argued that we may be legitimately skeptical of some particularly famous philosophical intuitions in both the philosophy of mind and in epistemology