Moral progress is often modeled as an increase in moral knowledge and understanding, with achievements in moral reasoning seen as key drivers of progressive moral change. Contemporary discussion recognizes two (rival) accounts: knowledge-based and understanding-based theories of moral progress, with the latter recently contended as superior (Severini 2021 ). In this article, we challenge the alleged superiority of understanding-based accounts by conducting a comparative analysis of the theoretical advantages and disadvantages of both approaches. We assess them based on their potential (...) to meet the following criteria: (i) moral progress must be possible despite evolutionary and epistemic constraints on moral reasoning; (ii) it should be epistemically achievable to ordinary moral agents; and (iii) it should be explainable via doxastic change. Our analysis suggests that both accounts are roughly equally plausible, but knowledge-based accounts are slightly less demanding and more effective at explaining doxastic change. Therefore, contrary to the prevailing view, we find knowledge-based accounts of moral progress more promising. (shrink)