Phaedra explores the destructive power of the passions, especially when human nature lacks the will or strength to control them. Viewed from a philosophical or Stoic perspective, the play highlights the importance of virtue ethics and of using reason to regulate one’s emotions. The characters all come to ruin because they fail to behave rationally and give in to their destructive impulses.

Phaedra, from whom the play derives its title, highlights this theme. Phaedra is perhaps the most complex character in the play. In the first act, she rationally analyzes and discusses her feelings in an almost detached manner. She understands that her feelings for Hippolytus are inappropriate, and even tries to curb herself at times. Yet Phaedra ultimately fails to control herself. This is at least in part because she believes that she simply cannot do so, that she suffers what fate or the gods have decreed. Phaedra is convinced that reason is impotent before such forces: “What can reason do? Passion, passion rules” (184).

Phaedra refuses to accept the Nurse’s insistence that she must want to control her passions: Phaedra repeatedly retorts that she does want to be good, but is unable to be so.