Understanding and empathy on the part of those in privileged positions are often cited as powerful tools in the fight against oppression. Too often, however, those in positions of power assume they know what it is like to be less well off when, in actuality, they do not. This kind of assumption represents a thinking vice we dub synecdoche epistemic arrogance. In instances of synecdoche epistemic arrogance, a person who has privilege wrongly assumes, based on limited experiences, that she can (...) know what it is like to experience a particular form of oppression. We argue two main points. First, synecdoche epistemic arrogance can lead to a variety of moral harms. Second, synecdoche epistemic arrogance is often tied to other troubling epistemic patterns, which we discuss in the context of disability and race simulations. Overall, the essay helps demonstrate how synecdoche epistemic arrogance can contribute to injustice. (shrink)