Each chapter of Dune begins with an epigraph excerpted from the fictional writings of the character Princess Irulan. In forms such as diary entries, historical commentary, biography, quotations and philosophy, these writings set tone and provide exposition, context and other details intended to enhance understanding of Herbert's complex fictional universe and themes.
Environmentalism and ecology
Dune has been called the "first planetary ecology novel on a grand scale." After the publication of Silent Spring by Rachel Carson in 1962, science fiction writers began treating the subject of ecological change and its consequences. Dune responded in 1965 with its complex descriptions of Arrakis life, from giant sandworms (for whom water is deadly) to smaller, mouse-like life forms adapted to live with limited water. The inhabitants of the planet, the Fremen, must compromise with the ecosystem in which they live, sacrificing some of their desire for a water-laden planet to preserve the sandworms which are so important to their culture. Dune was followed in its creation of complex and unique ecologies by other science fiction books such as A Door into Ocean (1986) and Red Mars (1992). Environmentalists have pointed out that Dune's popularity as a novel depicting a planet as a complex—almost living—thing, in combination with the first images of earth from space being published in the same time period, strongly influenced environmental movements such as the establishment of the international Earth Day.
Lorenzo DiTommaso compared Dune's portrayal of the downfall of a galactic empire to Edward Gibbon's Decline and Fall of the Roman Empire which argues that Christianity led to the fall of Ancient Rome. In "History and Historical Effect in Frank Herbert's Dune" (1992), Lorenzo DiTommaso outlines similarities between the two works by highlighting the excesses of the Emperor on his home planet of Kaitain and of the Baron Harkonnen in his palace. The Emperor loses his effectiveness as a ruler from excess of ceremony and pomp. The hairdressers and attendants he brings with him to Arrakis are even referred to as "parasites." The Baron Harkonnen is similarly corrupt, materially and sexually decadent. Gibbon's Decline and Fall blames the fall of Rome on the rise of Christianity. Gibbon claimed that this exotic import from a conquered province weakened the soldiers of Rome and left it open to attack. Similarly, the Emperor's Sardaukar fighters are little match for the Fremen of Dune because of the Sardaukar's overconfidence and the Fremen's capacity for self-sacrifice. The Fremen put the community before themselves in every instance, while the world outside wallows in luxury at the expense of others.
Middle Eastern references
Many words, titles and names (e.g. the Padishah Emperor Shaddam IV, Hawat, Bashar, Harq-al-Ada) in the Dune universe as well as a large number of words in the language of the Fremen people are derived or taken directly from Persian and Arabic (e.g. erg, the Arabic word for a broad flat landform, is used frequently throughout the novel). Paul's name (Muad'Dib) means in Arabic 'the teacher or maker of politeness or literature'. The Fremen language is also embedded with Islamic terms such as, jihad, Mahdi, Shaitan, and the personal bodyguard of Paul Muad'Dib Fedaykin is a transliteration of the Persian Feda'yin. As a foreigner who adopts the ways of a desert-dwelling people and then leads them in a military capacity, Paul Atreides' character bears many similarities to the historical T. E. Lawrence.
Paul's approach to power consistently requires his upbringing under the female-oriented Bene Gesserit, who operate as a long-dominating shadow government behind all of the great houses and their marriages or divisions. A central theme of the book is the connection, in Jessica's son, of this female aspect with his male aspect. In a Bene Gesserit test early in the book, it is implied that people are generally "inhuman" in that they irrationally place desire over self-interest and reason. This applies Herbert's philosophy that humans are not created equal, while equal justice and equal opportunity are higher ideals than mental, physical, or moral equality. Margery Hourihan even calls the main character's mother, Jessica, "by far the most interesting character in the novel" and pointing out that while her son approaches a power which makes him almost alien to the reader, she remains human. Throughout the novel, she struggles to maintain power in a male-dominated society, and manages to help her son at key moments in his realization of power.
I am showing you the superhero syndrome and your own participation in it.—Frank Herbert
Throughout Paul's rise to superhuman status, he follows a plotline common to many stories describing the birth of a hero. He has unfortunate circumstances forced onto him. After a long period of hardship and exile, he confronts and defeats the source of evil in his tale. As such, Dune is representative of a general trend beginning in 1960s American science fiction in that it features a character who attains godlike status through scientific means. Eventually, Paul Atreides gains a level of omniscience which allows him to take over the planet and the galaxy, and causing the Fremen of Arrakis to worship him like a god. Author Frank Herbert said in 1979, "The bottom line of the Dune trilogy is: beware of heroes. Much better [to] rely on your own judgment, and your own mistakes." He wrote in 1985, "Dune was aimed at this whole idea of the infallible leader because my view of history says that mistakes made by a leader (or made in a leader's name) are amplified by the numbers who follow without question."
Juan A. Prieto-Pablos says Herbert achieves a new typology with Paul's superpowers, differentiating the heroes of Dune from earlier heroes such as Superman, van Vogt's Gilbert Gosseyn and Henry Kuttner's telepaths. Unlike previous superheroes who acquire their powers suddenly and accidentally, Paul's are the result of "painful and slow personal progress." And unlike other superheroes of the 1960s—who are the exception among ordinary people in their respective worlds—Herbert's characters grow their powers through "the application of mystical philosophies and techniques." For Herbert, the ordinary person can develop incredible fighting skills (Fremen, Ginaz swordsmen and Sardaukar) or mental abilities (Bene Gesserit, Mentats, Spacing Guild Navigators).
Early in his newspaper career, Herbert was introduced to Zen by two Jungian psychologists. Throughout the Dune series and particularly in Dune, Herbert employs concepts and forms borrowed from Zen Buddhism. The Fremen are Zensunni adherents, and many of Herbert's epigraphs are Zen-spirited. In "Dune Genesis" he wrote:
What especially pleases me is to see the interwoven themes, the fuguelike relationships of images that exactly replay the way Dune took shape. As in an Escher lithograph, I involved myself with recurrent themes that turn into paradox. The central paradox concerns the human vision of time. What about Paul's gift of prescience-the Presbyterian fixation? For the Delphic Oracle to perform, it must tangle itself in a web of predestination. Yet predestination negates surprises and, in fact, sets up a mathematically enclosed universe whose limits are always inconsistent, always encountering the unprovable. It's like a koan, a Zen mind breaker. It's like the Cretan Epimenides saying, "All Cretans are liars."