Reliabilism

Reliabilism, a category of theories in the philosophical discipline of epistemology, has been advanced both as a theory of knowledge and of justified belief. As a theory of knowledge, reliabilism on one formulation can be roughly stated as follows:

One knows that p (p stands for any proposition--e.g., the sky is blue) if, and only if, (1) one believes that p, (2) p is true, and (3) one has arrived at the belief that p through some reliable process.

As a theory of justified belief, reliabilism can be formulated roughly as follows:

One has a justified belief that p if, and only if, the belief is the result of a reliable process.

Leading proponents of reliablist theories of knowledge and justification have included Alvin Goldman, Marshall Swain, and more recently, Alvin Plantinga. Goldman's article "A Causal Theory of Knowing" (need full reference) is generally credited as being the seminal statement of the theory, though D. M. Armstrong is also regarded as an important source of the theory.

The third clause is generally presented as an alternative to the notion that you must be justified in believing X in order for that belief to be true. The philosophical term Justification is being used here in its standard epistemological sense, to indicate that any belief you hold must be based on only the evidence available to you in order to qualify as knowledge. The distinction the reliablist makes is that the someone does not need to know that the process she is using to form a belief is a reliable belief formation mechanism, as long as process she uses actually is reliable, she is warranted in calling that belief knowledge.

This means that reliabilism is based on the controversial claim that at least some of the relationships which are essential to knowledge formation may be external to the consciousness of the person forming the belief.

Many reliabilists also subscribe to the causal theory of belief.