How does the author describe Ishmael's past?

The gorilla, named Ishmael, can communicate telepathically. Communicating with him in this fashion, the narrator learns Ishmael’s background - in which the gorilla was stolen from the wild and displayed in a menagerie, then rescued by a Holocaust survivor who taught him his name and how to learn. Impressed, the narrator decides to accept his teachings, returning to Ishmael's office throughout the story.