Beginning with Darwin's notorious chart listing reasons to wed and not to wed, Heiligman has created a unique, flowing, and meticulously researched picture of the controversial scientist and the effect of his marriage on his life and work. Using the couple's letters, diaries, and notebooks as well as documents and memoirs of their relatives, friends, and critics, the author lets her subjects speak for themselves while rounding out the story of their relationship with information about their time and place.