 Roorda’s final challenge to extremal probability appeals to corrigibility, according to which it is reasonable to believe that at least some of my beliefs may need to be abandoned in light of new information. However, if partial beliefs are updated via Bayesian conditioning, I can never cease to believe any of my full beliefs since if \(\Pr(A)=1\) it follows that \(\Pr(A|E)=1\) for all \(E\) such that \(\Pr(E)&gt;0\). If we believe in Bayesian conditioning, extremal probability seems to entail that I cannot revise any of my full beliefs in light of new information.