I think that the reader can identify with the narrator in "Cathedral," making him a sympathetic character.
The narrator is a sympathetic character from the story's opening. The narrator talks about how his "idea of blindness came from the movies." This detail makes us relate to the narrator because of it shows how biased we can be. We see the narrator as sympathetic because many of us have been in similar situations where something external has formed our initial predispositions. The narrator is also sympathetic because he initially does not want his world to be disrupted. We can relate to someone who says that a visit "was not something I looked forward to." In these ways, the story opens with the narrator as someone towards whom we have sympathy or with whom we can identify.
The ending of the story is another instant where we experience sympathy towards the narrator. He has shared a moment with the blind man in the drawing of the cathedral. When the blind man tells the narrator to keep his eyes closed, he must try something new. He experiences life from another person's point of view. This experience makes us feel sympathy towards him. We identify with him because we see how much a casual encounter has changed him. It creates sympathy because we understand how important it is to be open to new experiences in our lives.