 Perhaps surprisingly, it is also possible to undergo a static belief change upon receipt of the true formula \eqref{MF} from a completely trustworthy source. For this to happen, we must think of the “situation” with regard to the truth of p and the agent’s beliefs about this truth as completely static, like a “snapshot in time”. We then look at how the agent’s beliefs about that static snapshot might change upon receipt of the completely trustworthy information that \eqref{MF} was true in the moment of that snapshot. To make sense of this, it might be helpful to think of it this way: the agent learns something in the present about what was true of her situation in the past. So her present views about her past beliefs change, but the past beliefs remain fixed. It is as though the agent studies a photograph of herself from the past: her “present self” changes her beliefs about that “past self” pictured in the photograph, fixed forever in time. In a certain respect, the “past self” might as well be a different person: 