When Doug finds out Skeeter's a genius, he scans Skeeter's bookshelf. Among the books are real-life titles such as: "A Critique of Pure Reason" (Immanuel Kant), "Decline and Fall of the Roman Empire" (Edward Gibbon), "Orlando Furioso" (Ludovico Ariosto), "Principia Mathematica" (Bertrand Russell and Alfred North Whitehead), and "Tractatus Logico-Philosophicus" (Ludwig Wittgenstein).