Reliability Theories of Justified Credence

Reliabilists hold that a belief is doxastically justified if and only if it is caused by a reliable process. But since such a process is one that tends to produce a high ratio of true to false beliefs, reliabilism is on the face of it applicable to binary beliefs, but not to degrees of confidence or credences. For while (binary) beliefs admit of truth or falsity, the same cannot be said of credences in general. A natural question now arises: Can reliability theories of justified belief be extended or modified to account for justified credence? In this paper, I address this question. I begin by showing that, as it stands, reliabilism cannot account for justified credence. I then consider three ways in which the reliabilist may try to do so by extending or modifying her theory, but I argue that such attempts face certain problems. After that, I turn to a version of reliabilism that incorporates evidentialist elements and argue that it allows us to avoid the problems that the other theories face. If I am right, this gives reliabilists a reason, aside from those given recently by Comesan˜a and Goldman, to move towards such a kind of hybrid theory.