The idea of impersonation, I think, is central both to how writers think and imagine, and to what they write about. Not that all writers are drawn to impersonation as a theme; but all writers enact impersonation in the invention of character. One caveat: Writers who are impersonators in life cannot be honest writers of fiction. The falsehood will leach into the work. […] The imagination that deals with fictive authenticity depends absolutely on personal authenticity, because fiction depends on clarity of seeing. If you are not lucid about yourself, you are not going to be lucid about anything.
From “Cynthia Ozick” in Diane Osen, ed., The Book That Changed My Life: Interviews with National Book Award Winners and Finalists (2002).