The paper challenges William Alston’s argument against doxastic deontology, the view that we have epistemic duties concerning our beliefs. The core of the argument is that doxastic deontology requires voluntary control over our beliefs, which we do not have. The idea that doxastic deontology requires voluntary control is supposed to follow from the principle that ought implies can. The paper argues that this is wrong: in the OIC principle which regulates our doxastic duties the “can” does not stand for the (...) ability to shape our beliefs voluntarily. As an examination of everyday examples shows, it stands for cognitive competence, the reliable ability to acquire beliefs in compliance with the epistemic norms. The doxastic OIC principle asserts, in brief, that one is only obliged to believe something if one’s cognitive capacities are sufficiently strong. It is also explained why the doxastic duties do not require voluntary control as opposed to moral duties. This understanding of doxastic duties saves our everyday doxastic deontic judgments from Alston’s argument, but does not help the deontological conception of justification, which understands justification as not violating one’s epistemic duties. It actually provides another argument against the deontological conception: if the OIC regulating our doxastic duties is construed as suggested, the deontological conception of justification implies that one’s doxastic duties and, consequently, whether one’s belief is justified depend on one’s cognitive competence. Since cognitive competence varies from person to person, justification will not matter to truth and knowledge in the way epistemic justification is supposed to do. (shrink)