This masterpiece of introspection was published by Bellow (http://en.wikipedia.org/wiki/Saul_Bellow) in 1964.
The reader is given epistolary revelations in unsent letters from Moses E. Herzog whose life is a failure and whose wife has left him, but who remains defiant and wryly perceptive about the world around him.
368 pages in Penguin Modern Classics edition.
ISBN 978-0141184876
Saul Bellow