Some of the most famous writers of history have examined religious themes. Sometimes this is obvious, such as in Dante's "Inferno." Other works explore through metaphor, such as C.S. Lewis does throughout "The Chronicles of Narnia," in which numerous Christian stories and themes are examined through a fairy tale-like lens. In others, the theme may be one that examines the validity of religion itself. Dostoevsky, for example, exemplifies the conflict that exists between faith and doubt in "The Brothers Karamazov."
Politics and power is another theme explored throughout classic and contemporary literature. Shakespeare, for example, explored themes such as the corruption that power brings in plays such as "Macbeth" and "King Lear." Contemporary politics may be reflected with a more direct theme, such as in Arthur Miller's "The Crucible". He used the Salem witch hunt as a metaphor for the activities related to the paranoia about communism in the United States at that time.
Sex and sexuality have been explored through almost every conceivable angle through famous literature. Toni Morrison's "Beloved" looks at sexuality as a type of power and how manipulation and control is possible through the use of sexuality. From a classical perspective, Ovid's "Metamorphoses" looks at the questions of love and sex from many different angles, including how the two relate and if they can exist independently.
"The Lord of the Rings" trilogy explored many ideas, but one of the primary ones was a theme of environmentalism. It expressed how J.R.R. Tolkien believed that ultimately, technology might do more damage than good to the world. The Sherlock Holmes stories written by Sir Arthur Conan Doyle, on the other hand, express how technology is the advantage that the learned have over the masses. In fact, Holmes often relies on technology to solve his cases.