The philosophy in the "Meditations" of the Roman emperor Marcus Aurelius is unoriginal Stoicism, but the "Meditations" are still read for their literary merit and for the insight they give into the workings of the emperor's mind. Arthur Schopenhauer's philosophy is noted for the quality and readability of its prose, as are some of the works of the British Empiricists, such as Locke and Hume. Søren Kierkegaard's style is frequently regarded as poetic artistry as well as philosophical, especially in "Fear and Trembling" and "Either/Or". Friedrich Nietzsche's works such as "Thus Spoke Zarathustra" frequently resemble prose poetry and contain imagery and allusion instead of argument. Socrates appears in a highly fictionalized guise, as a comic figure and the object of mockery, in "The Clouds" by Aristophanes. In the play, Socrates appears hanging from a basket, where he delivers oracles such as:  Early Taoist philosopher Zhuang Zhou expressed his ideas primarily through short literary anecdotes and fables. The other major philosophers of the time appear as characters within these stories, allowing Zhuangzi to playfully explore their ideas and contrast them with his own, as he does with Laozi, Liezi, Hui Shi, and many others. Most prominently in his work is the presence of Confucius and his prominent disciples, who are sometimes used to undermine popular understandings of Confucian philosophy or to reinforce Zhuangzi's own understanding of how one lives in accordance with the Dao. Jorge Luis Borges is perhaps the twentieth century's preeminent author of philosophical fiction. He wrote a short story in which the philosopher Averroes is the chief protagonist, "Averroes's Search". Many plot points in his stories accurately paraphrase and epitomize the thought of major philosophers, including George Berkeley, Arthur Schopenhauer, and Bertrand Russell; he also attributes various opinions to figures including George Dalgarno. A key plot point in Umberto Eco's novel "The Name of the Rose" turns on the discovery of a mysterious book that turns out to contain a lost manuscript by Aristotle. Eco's later novel "Foucault's Pendulum" became the forerunner of a run of thrillers or detective fiction that toss around learned allusions and the names of historical thinkers; more recent examples include Dan Brown's "The Da Vinci Code" and "The Rule of Four" by Ian Caldwell and Dustin Thomason.