To avoid the problem of regress, externalists have put forward defeaters-based accounts of justification. The paper argues that existing proposals face two serious concerns: (i) They fail to accommodate related counterexamples such as Norman the clairvoyant, and, more worryingly, (ii) they fail to explain how one can be epistemically responsible in holding basic beliefs—i.e., they fail to explain how basic beliefs can avoid being arbitrary from the agent’s point of view. To solve both of these problems, a new, externalist, defeaters-based (...) account of justification is offered—viz., System Reliabilism. The core message of the view—and the way it deals with both (i) and (ii)—is the claim that the justificatory status of justified basic beliefs originates from being the undefeated outputs of a reliable, cognitively integrated system that is capable of defeating them. Simply put, to be candidates for being justified, basic beliefs must be epistemically responsible and to be so they must be undefeated while being defeasible. The paper also offers a detailed, naturalistic analysis of the notion of cognitive integration. This long-due, mechanistic account of cognitive integration is then used to argue that an additional advantage of System Reliabilism is its unique position to account for the as yet unexplained intuition that responsible beliefs are also likely to be true. (shrink)