We have seen that the quest for infallible foundations is a failure. The attempt to find infallible basic beliefs that guarantee their own truth to serve as a foundation yielded the most meager results. Fallibility infects almost all our beliefs. More important, however, is the fact that the infallibility of infallible beliefs may be opaque to the subject so that the subject has no idea that the beliefs are infallible.
[...] The idea that we might construct or reconstruct the edifice of knowledge from a set of basic beliefs whose truth is guaranteed and that guarantee the truth of all the rest was of extraordinary importance in the theory of knowledge. Had it been succesful, it would have provided us with a means of ensuring the truth of what we accept and avoiding the problems arising from the existence of justified false beliefs. Like other philosophical traditions, it taught us something different from what was originally intended. The lesson is that we are fallible in what we believe and must proceed without any guarantee of our success. The quest for truth, if based on a foundation of self-justified beliefs, must be based on a fallible foundation.
Keith Lehrer, Theory of Knowledge.