By the Jewish philosopher Martin Buber, from Elements of the Interhuman:
Let us now imagine two men, whose life is dominated by appearance, sitting and talking together. Call them Peter and Paul. Let us list the different configurations which are involved. First, there is Peter as he wishes to appear to Paul, and Paul as he wishes to appear to Peter. Then there is Peter as he really appears to Paul, that is, Paul’s image of Peter, which in general does not in the least coincide with what Peter wished Paul to see; and similarly there is the reverse situation. Further, there is Peter as he appears to himself, and Paul as he appears to himself. Lastly, there are the bodily Peter and the bodily Paul. Two living beings and six ghostly appearances, which mingle in many ways in the conversation between the two. Where is there room for any genuine interhuman life?