Say what you will about President Obama, he's definitely not a frivolous man. His somber, intellectual nature comes out clearly in his recent selection of Lauren Groff's novel Fates and Furies as his favorite book of 2015.

Obama's choice this year is a bit unusual since most of his favorite novels have political themes. Here are Obama's favorite novels, based on various reports over the years:

1. Fates and Furies

Author: Lauren Groff

Published: 2015

Summary: A seemingly perfect marriage between an artist and an actor survives not through the confession of truth but through the ability of both husband and wife to conceal secrets that, if revealed, might weaken or destroy the relationship.

2. Song of Solomon

Author: Toni Morrison

Published: 1995

Summary: The son of a wealthy black property owner travels to his hometown in search of a hidden cache of money and instead discovers how his life, despite his position of relative privilege, has constantly been molded by racism and the historical fact of slavery.

3. For Whom The Bell Tolls

Author: Ernest Hemingway

Published: 1940

Summary: A young man learns about love, life and the evils of fascism through experiencing hardship and violence as a volunteer guerilla fighter during the Spanish Civil War. Generally considered Hemingway's best novel.

4. The Power and the Glory

Author: Graham Greene

Published: 1940

Summary: A clergyman only identified as the "whiskey priest" flees government assassins while haunted by an affair in his past and struggling with his faith in God and his seemingly unconquerable alcoholism.

5. The Quiet American

Author: Graham Greene

Published: 1955

Summary: During the French occupation of Vietnam, a British reporter tries to prevent a feckless American diplomat from causing increased violence and torment, while they are both having an affair with the same Vietnamese woman.

6. The Golden Notebook

Author: Doris Lessing

Published: 1962

Summary: A successful author struggling with mental illness finds sanity by condensing into a single volume the four diaries she kept while she was growing up a white girl in colonial Africa during the cold war.

7. Cancer Ward

Author: Alexander Solzhenitsyn

Published: 1968

Summary: The relationships of a group of cancer patients in Soviet Russia two years after Stalin's death reveals deeply conflicting and conflicted attitudes they have, on the edge of death, to both their lives and to contemporary Russian culture.

8. In Dubious Battle

Author: John Steinbeck

Published: 1936

Summary: A communist organizer helps organize a labor union among fruit pickers, hoping that a strike will call attention to his cause. In the process, he find himself at war, not with the world, but with himself.

9. Of Mice and Men

Author: John Steinbeck

Published: 1937

Summary: A pair of itinerant laborers seek to advance themselves from abject poverty to the lower middle class, only to be thwarted by the limitations of their background and their human need for companionship.

10. All the King's Men

Author: Robert Penn Warren

Published: 1946