The problem of scientific disregard is the problem of accounting for why some putative theories that appear to be well-supported by empirical evidence nevertheless play no role in the scientific enterprise. Laudan and Leplin suggest (and Hoefer and Rosenberg concur) that at least some of these putative theories fail to be genuine theoretical rivals because they lack some non-empirical property of theoreticity. This solution also supports their repudiation of the thesis of underdetermination. I argue that the attempt to provide criteria (...) of theoreticity fails, that there is a Bayesian solution to the problem of scientific disregard that fares better, and that this successful solution supports a distinctively Bayesian version of the underdetermination thesis. (shrink)