 Turn now from miracles to the topic of revelation, of God speaking directly to humans and telling them what's good, what's right, how they should live, and so on. Most religious traditions have a kind of revelation story about them. So for instance, we can see here Moses bringing the commandments down from Mount Sinai. We can see Muhammad receiving the words of Gabriel in the cave. We can see Joseph Smith receiving the revelation from the angel Moroni. We can see Vastitha, the Hindu sage, and we can see Elrond Hubbard's book Dianetics. Each of these is treated by some individuals as a source of revelation. But not all revelations are recognized by every religion, and even within a particular religion, some alleged revelations are rejected by some groups. So for instance, in the center here, we see the first page of the Gospel of Thomas, which came from the Nag Hammadi Codex number two, which was recently discovered in Egypt. This is an alleged fifth Gospel of the Christian New Testament, which both Protestants and Catholics tend to reject. So when it comes to revelation, it's not just a matter of there being some revelation. Every religious tradition wants to include all and only the relevant revelations that come with its tradition. And that means that even between, for instance, Protestants and Catholics, the recognized canon differs. The Catholic Church recognizes seven books of the Old Testament, along with additional verses and two other books as part of the canon, that the Protestants reject. These include, for instance, the books of the Maccabees. So even within the Christian tradition, there's disagreement about what counts as revelation and what doesn't. That means that we need some way of tracing back the texts that we have now to their original source and distinguishing reliable and trustworthy sources from sources that are unreliable or untrustworthy. And that also means that unless we can track the conduits carefully, we won't even be able to identify the sources in the first place. This was a topic not just in the Christian tradition, but also in Islam, where the sayings of the prophet, known as Hadith, were a very important topic. Hadith were meant to be the first person report of things that Muhammad said. And that means that in order to authenticate Hadith as legitimate, one had to be able to trace from oneself to the person who told one about a Hadith all the way back through a reliable chain of testimony to one of Muhammad's companions. And a whole tradition of Hadith scholarship, much of which included women conduits in North Africa sprang up in the centuries after Muhammad's death. Avicenna, arguably the most important philosopher of the Islamic world, created what might be the first social epistemology partially in response to Hadith scholarship. He was upset that Hadith scholarship tended to become too quantitative. In other words, that as long as three sources could be identified for a given Hadith, then it was treated as authenticated. And he said that just counting the number of conduits is not adequate. In addition, we need to know about the trustworthiness of the conduits and of the sources in themselves. In other words, Avicenna said that in order to accept testimony third, fourth, or fifth hand, we need some kind of account of the intellectual virtues and potentially intellectual vices of the other nodes in the network of the source and of the conduits. Avicenna had a very interesting social epistemology that is similar to certain epistemologies that we have in contemporary analytic philosophy. He argued that knowledge always depends on some kind of second-order doxastic state, which means, in other words, that when you believe the truth, that on its own doesn't count as knowledge, you also need to believe correctly that you're believing the truth. So you need to have a second-order belief about your first-order belief. And he distinguished various sources as justifying different levels of confidence in this second-order belief. He thought, for instance, that introspection was highly reliable and that if you arrive at a first-order belief through introspection, then your second-order belief about it might count as certitude or as a strong kind of knowledge. He distinguished from this various other sources that are less reliable, including intuition, where he thought that if you have an intuition, perhaps you can have a second-order belief in it, but it should be less strong than the one based on introspection. And then even less confident beliefs should come from experience and from chains of testimony, and we should, in general, be not confident at all in our beliefs based on mere common opinion or authority, which in his tradition is known as taklid. An alternative to focusing on conduits for revelation has to do with focusing on sources. For instance, early Buddhists who were criticizing Hindu traditions claimed that various sages were ignorant of the true path to union with Brahma and that because the original sources of alleged revelation were ignorant, in other words, because original sources lacked the required epistemic virtues, the revelation itself could be disregarded. By contrast, Hindu logicians who opposed this argument held that the Buddha too was fallible because he was human, and that the only trustworthy source is God, who is infallible and morally virtuous. So they held a very strong position that the ultimate source of revelation and testimony about revelation must not just be intellectually or epistemically virtuous in some way, but must be outright infallible. That's a very strong requirement that we don't tend to expect about other people, of course. So what this suggests is that to responsibly believe in either miracles or revelation, one needs to count on a chain that includes an intellectually virtuous, perhaps even infallible source, an intellectually virtuous conduit or multiple conduits, and intellectually virtuous receiver, in other words, oneself. And that means that if any of these links in the chain is broken, we should disbelieve in reports about miracles or revelation.