 Some form of stability is widely considered to be a necessary condition for  knowledge. Socrates propounds such a view in the  Meno. Paxson Jr. and Lehrer (1969) champion such a view in the epistemology literature post-Gettier (1963). However, stability is not usually mooted as a condition of  belief. Raidl and Skovgaard-Olsen (2017) claim that Leitgeb’s stability condition is more appropriate in an analysis of knowledge and too stringent a condition on belief. A defender of the Humean thesis might say that every  rational belief is possibly an instance of knowledge. Since knowledge is necessarily stable, unstable beliefs are  ipso facto not known.