The Oedipus complex is a recurring idea in the book. Kristeva's philosophical heritage is composed primarily of post-modernism and Freudian psychoanalysis. Her work is largely a continuation of the project begun by Jacques Lacan and others to apply the linguistic insights of post-modernism to the psychoanalytic method of Freud. It is important, then, to realize that Kristeva is not a "pure" Freudian; indeed, she explicitly disagrees with him several times in the book. Nonetheless, any reading of the text will immediately reveal that she is, nonetheless, much indebted to his work. One of the most important Freudian insights Kristeva uses is the Oedipus complex. According to Freud, when a child (particularly a boy—but there is thought to be an equivalent experience for a girl) grows up, he begins to sexually desire his mother.