What is the theme in the short story Paul's Case by Willa Cather?

The theme of a story is the idea or concept that the story examines. One theme in Paul's Case is alienation, the fact that Paul has dreams different from those around him, or from what his father wants for him. Another is desire, longing, or envy, because he is unlikely to ever fulfill those dreams.

This can also be seen as the dichotomy between life and art. It is Paul's dissatisfaction with his life, and his yearning for a different one, that drives him to his actions.