 To see how all of this works, let us consider a simple example scenario in which our two agents a and b are discussing the truth of two statements p and q. In the course of the conversation, it becomes common knowledge that neither agent has any information about q and hence neither knows whether q is true, though, as it turns out, q happens to be true. However, it is common knowledge that agent b is an expert about an area of study whose body of work encompasses the question of whether p is true. Further, agent b publicly delivers his expert opinion: p is true. Agent a trusts agent b’s expertise and so she (agent a) comes to believe that p is true. But her trust is not absolute: a still maintains the possibility that agent b is wrong or deceitful; hence she is willing to concede that her belief of p is incorrect. Nevertheless, she does trust b for now and comes to believe p. Unfortunately, her trust is misplaced: agent b has knowingly lied; p is actually false. We picture this scenario in Figure 8. 