The Unbearable Lightness of Being (1984), by Milan Kundera, is a philosophic novel about a man and his two women and their lives in the Prague Spring of the Czechoslovak Communist period in 1968. he characters are Tomáš, a successful surgeon; his wife Tereza, a photographer anguished by his infidelities; Sabina, a free-spirit artist, who is Tomáš’s lover; and the secondary characters Franz, the Swiss university professor lover of Sabina; and Simon, Tomáš’s estranged son from an earlier marriage. Challenging Friedrich Nietzsche’s concept of eternal recurrence (the universe and its events have already occurred and will recur ad infinitum), the story’s thematic meditations posit the alternative that each person has only one life to live, and that which occurs in that life, occurs only once shall never occur again — thus the “lightness” of being; whereas eternal recurrence is the “heaviness” threatening the meaning of said life.