Accounts of public reason disagree as to the conditions a reason must meet in order to qualify as public. On one prominent account, a reason is public if, and only if, it is shareable between citizens. The shareability account, I argue, relies on an implausibly demanding assumption regarding the epistemic capabilities of citizens. When more plausible, limited, epistemic capabilities are taken into consideration, the shareability account becomes self‐defeating. Under more limited epistemic conditions, few, if any, reasons will be shareable between (...) all reasonable citizens, making the shareability account so demanding that it precludes public reasoning altogether. (shrink)