Abstract: According to a standard principle in free speech law, the remedy for falsehoods is "more speech," not enforced silence. But empirical research demonstrates that corrections of falsehoods can actually backfire, by increasing people’s commitment to their inaccurate beliefs, and that presentation of balanced information can promote polarization, thus increasing preexisting social divisions. We attempt to explain these apparently puzzling phenomena by reference to what we call Asymmetric Bayesianism: purported corrections may be taken to establish the truth of the proposition that is being denied, and the same information can have diametrically opposite effects if those who receive it have opposing antecedent convictions. In our primary model, recipients whose beliefs are buttressed by the message, or a relevant part, rationally believe that it is true, while recipients whose beliefs are at odds with that message, or a relevant part, rationally believe that the message is false (and may reflect desperation). We also show that the same information can activate radically different memories and associated convictions, thus producing polarized responses to that information, or what we call a memory boomerang. These explanations help account for the potential influence of "surprising validators." Because such validators are credible to the relevant audience, they can reduce the likelihood of Asymmetric Bayesianism, thus ensuring that corrections are persuasive and also promoting agreement.