The Reliability Theory of Knowledge and the KK-Principal

According to the Reliability Theory of Knowledge, knowing a proposition does not imply that you know that you know it. In contrast the KK-principal which says that if S knows that P, then S knows that he knows P. Such a theory is convenient for the skeptics who, in following the principal, do not believe they have knowledge and therefore do not have knowledge. Such an idea applied to all propositions is simply not reasonable for example, if Sam has blond hair, but he does not believe he has blond hair, therefore he does not know he has blond hair, then he does not have blond hair.

The Reliability Theory of Knowledge is so offensive to Skeptics because it largely involves externalism, the idea that one can have a justified belief without having access to the evidence for it. It is similar to the theory of Truth Tracking where people are basically thermometers and can tell the temperature, or whether the dog is in the room or the television is on, merely by sensing it (petting and smelling the dog, hearing and seeing the television) just like a thermometer senses the external temperature. However, Reliabilism (the parent of the Reliability Theory of Knowledge as it in itself focuses more on justification than knowledge) formulates a theory of justified belief as "One has a justified theory of p iff the belief is a result of a reliable process". Reliabilists agree that knowledge is justified, true, belief and also take into account the Gettier cases where it is possible to be right about something by accident, which coincides with evidentialist theories. However, Reliabilists do not care about the actual evidence. Instead Reliabilists are concerned with how the beliefs were formed and if they were formed by some reliable process so "S is justified in believing p iff S is justified in believing that S's source for p is reliable." For example, "Paul is rich if he has made money on his own or is he is the child of rich parents." The example does not deal with what rich actually is, but the concept is not circular in that the second clause of the sentence can be reformulated as "Paul is the son of rich parents" as it explicitly states a way into being rich.