Who is Nathan Zuckerman from American Pastoral and what is their importance?

Nathan Zuckerman is the narrator. He is the alter-ego of Philip Roth, the author, and has appeared in a number of other books by Roth. Zuckerman is a sixty-two-year-old writer living alone and isolated in a hamlet in western Massachusetts. He had surgery for prostate cancer a year earlier, and the treatment left him impotent and incontinent.