Headed though, we have considered the justification of beliefs by other beliefs. An underlying assumption has been that, at least in principle, the epistemic subject has access to the justification of a belief. The foundation lists can trace back or reduce her belief to a foundational layer of basic beliefs ultimately supporting it. The coherent list is or can become aware that her belief hangs together with other beliefs, constituting a coherent web of beliefs and so on. What these approaches to justification share is internalism. Factors internal to the epistemic subject determine whether or not her belief is justified. However, triggered by the Katia problem, which we discussed in the second clip, approaches to justification have been developed over the last half-century that exemplify externalism. Only factors external to the epistemic subject determine whether or not her belief is justified. According to externalism then, the epistemic subject needs no access to the justification of a belief. Reliable is such an externalist theory of justification. For the basic notion of reliability, we can think of the debate about the media and fake news. Journals or networks that's often published news that turns out to be false are unreliable. Readers, listeners, or viewers should not rely on them. They should rather base their beliefs on the information they obtain from journals and networks that publish more truths grounded in facts. In this context, being reliable is a function of being truth conducive. The degree of reliability of media depends on the ratio of true to false beliefs they tend to produce. Similarly, Goldman invites us to carefully consider processes of belief formation. Some processes like guesswork, hasty generalization, or wishful thinking are clearly unreliable, in that the beliefs that are formed by them are false. By contrast, belief-forming processes like standards, perceptual processes and good reasoning are reliable. They tend to produce more true than false beliefs. Hence, reliabilism proposes that a belief is justified if and only if it has been formed by a reliable process of belief formation, and whether the reliability of the process is defined in terms of its tendency to form beliefs that are true rather than false. The first objection to reliabilism is the new evil demon problem. Suppose that in some scenario, your counterparts, that is, your local representative has exactly the same perceptual experiences as you have, and forms exactly the same perceptual beliefs as you do. However, there is one all important difference, in contrast to you, your counterpart is systematically misled by an evil demon. Say, your counterpart is a brain-in-a-vat. As a result, almost all of your counterparts' perceptual beliefs are false, must qualify the perceptual processes by which they are formed as highly unreliable. However, the input is the same. You and your counterpart have the same perceptual experiences, and the output is the same as well, you and your counterpart form the same perceptual beliefs. If your perceptual beliefs are justified, your counterparts' perceptual beliefs should be justified as well, shouldn't they? A second problem for reliabilism is due to bonjur. Suppose that Norman is a reliable clairvoyance, but has no clue whatsoever as to his extraordinary cognitive power. He's not aware of the fact that clairvoyance exists, nor that he is himself versed in it. Suppose furthermore that one day out of the blue without any evidence, but resulting from his clairvoyant power, Norman forms a belief that the president is in New York City, and that is happens to be true. According to bonjur, Norman's belief is not justified though it meets the criteria of reliabilism, it results from a reliable process. A third problem for reliabilism is known as the generality problem. One can consider processes of belief formation at different levels of abstraction. This raises the difficult question, which level is irrelevant to justification? Consider our additional example in the first clip, your current experiences justify your belief that you are watching this clip. Is that because perception qualifies as a reliable process of belief formation or is it a little bit more specific because visual perception is reliable, or still more specific, visual perception in favorable light conditions and so on? One can continue to conceive of the process of belief formation in a less and less general way until it is so detailed that your current belief that you are watching this clip is the only belief resulting from your current process of belief formation in fullest detail. One of the major advantages of reliabilism is that, unlike internalism, it allows for what Sosa calls animal knowledge, the significant part of human knowledge that consists in first-order, reliably produced true belief or apt belief. Again, your first-order true belief that you are now watching this clip is reliably formed on the basis of perception and perhaps also a reliable bit of introspection. However, according to Sosa's own hybrids accounts, human knowledge is not restricted to animal knowledge. You can upgrade your apt belief to what Sosa calls reflective knowledge by reflecting on how your apt belief fits coherently with other beliefs you have. Like for instance, your belief that you are watching the module on Canvas, your belief that you are following this course and so on.