The Lord of the Rings presents a sharp polarity between good and evil. Orcs, the most maligned of races, are in one interpretation a corruption of the mystically exalted race of the Elves. Minas Morgul, the Tower of Sorcery, home of the Lord of the Nazgûl, the most corrupted King of Men, directly opposes Minas Tirith, the Tower of Guard and the capital of Gondor, the last visible remnant of the ancient kingdom of Men in the Third Age. Mordor, the land of the Dark Lord Sauron, is opposed to Gondor and to all free peoples. These antitheses, though pronounced and prolific, are sometimes considered to be too polarizing, but they have also been argued to be at the heart of the structure of the entire story. Tolkien's technique has been seen to confer literality on what would in the primary world be called metaphor and then to illustrate [in his secondary world] the process by which the literal becomes metaphoric. The theologian Fleming Rutledge argues, on the other hand, that Tolkien aims instead to show that no definite line can be drawn between god and evil, because 'good' people can be and are capable of evil under certain circumstances.