What are the motifs in The Immoralist by Andre Gide?

Life and death are recurring ideas of The Immoralist. During the course of the novel, Michel and then his wife are brought to the brink of death. While on their honeymoon, Michel becomes gravely ill from tuberculosis. Although he eventually recovers his health, Marceline later becomes ill from tuberculosis, which she had contracted while nursing him through his illness. Marceline's illness causes her to have a miscarriage, and she herself soon dies.