LitCharts assigns a color and icon to each theme in The Unbearable Lightness of Being, which you can use to track the themes throughout the work.
Time, Happiness, and Eternal Return
Lightness, Weight, and Dichotomies
Sex, Love, and Duality of Body and Soul
Words and Language
Power, Politics, and Inequality
Summary
Analysis
The editor tells Tomas that he really enjoyed the Oedipus article, and Simon comments that some ideas are very powerful. Tomas says that because of the Oedipus article, he can no longer practice as a doctor, but the editor assures Tomas that his article saved lives. Tomas doesn’t know about that, he says, but he is sure he saved lives as a surgeon. Simon says that ideas save lives, too, and it is Tomas’s “duty to sign.” Tomas hands the petition back and refuses to sign.
Tomas clearly disagrees with the Communist regime, but he doesn’t want to give them a reason to come after him again. Tomas knows that those who sign such a petition will be smeared publically by the regime. Tomas clearly does not like that Simon has told him what his “duty” is, which may be related to Tomas’s guilt for abandoning Simon and his “duty” as a father.