Whether by Providence or a random swerve of the atoms, it happened that Abraham Lincoln and Charles Darwin both were born on February 12, 1809. The bicentennial of this pregnant coincidence is the occasion for Adam Gopnik’s Angels and Ages: A Short Book about Darwin, Lincoln, and Modern Life. The title alludes to a resonant ambiguity over just what Edwin Stanton said at the president’s deathbed in 1865. Did his secretary of war commend Lincoln “to the angels” or “to the ages”? To whatever remained of the old hierarchical cosmos, or to the record of great but strictly human endeavor?