Regarding "The Lady with the Pet Dog," two short stories, one by Chekhov and one by Oates, one way to develop a theory of the stories to determine the authors' understandings of adulterous relationships is to examine a thematic concern from each story. Other ways to accomplish this may to be to examine character interaction, character traits, various expressions of emotions, various expectations, epiphanies (moments of enlightenment) that characters have, etc. For now, for illustration purposes, we'll examine the thematic concerns that are expressed in the paradoxes in the stories.
In Chekhov's version, Chekhov's final expression of his understanding of Gurov's and Anna's adulterous relationship is represented in the story's paradox (paradox: what seemingly cannot be true nonetheless is true, e.g., letting go of self brings the fulfillment of self). Gurov lives a life in which he has no deep bond with his wife, who is cold and distant, and so he contents himself with frequent affairs of the heart in which he gives momentary happiness to various women until he gets bored with them and pleasantly calls the affairs off. He never feels deeply moved yet is proud of the fact that he gives happiness to the various women he encounters. He believes this is a very good life and one that is profoundly real when coupled with his work and social standing.
After parting from Anna, however, Gurov's anticipated boredom and detachment fail to occur and he finds himself more and more preoccupied with thoughts of her. Over time, after they start seeing one another again, he comes to realize that she has become his real life and the real life he did have in his work, social status, wife and family has faded to a mere phantom experience in which his thoughts, heart and attention are always elsewhere. Gurov's paradoxical turn occurs when suddenly his public life is seen by him as unreal while his hidden secret life is seen as real. Interestingly, Anna never experiences a paradoxical turn; she is miserable and ashamed because of her "fall," and she remains miserable and ashamed of her "fall." The thematic concern expressed in the paradox is that public life of wealth, position and family is unreal while a forbidden life of love and compassion fraught with anguish is real.
In Oates' version, Oates' final expression of her understanding of Anna's adulterous relationship is represented in her story's paradox. Anna has been psychologically unhappy and unfulfilled in her marriage and feeling guilty and torn about her place in life, or about her marriage's place in her life. She is feeling psychologically unstable, which is why she goes to the beach house. Anna finds that a marriage that is not a love and a marriage of the heart is insupportable. After she starts (and stops then starts) her affair, she also finds falseness insupportable. Anna's paradoxical turn occurs when she realizes that her guilt-ridden relationship produces a real "marriage" of the heart while her lawful relationship produces emptiness of the heart. The thematic concern expressed in the paradox is that a true marriage of the heart is the relationship that has been driving her to suicide and is unlawful, while lawful marriage is false. Therefore Chekhov and Oates have similar understands of adulterous affairs, in terms of these paradoxical themes, in the sense that both perceive adultery to paradoxically lead to personal fulfillment and happiness, even if in the midst of tears.