Repetition () is an 1843 book by Søren Kierkegaard and published under the pseudonym Constantin Constantius to mirror its titular theme. Constantin investigates whether repetition is possible, and the book includes his experiments and his relation to a nameless patient known only as the Young Man. The Young Man has fallen in love with a girl, proposed marriage, the proposal has been accepted, but now he has changed his mind. Constantin becomes the young man's confidant. Coincidentally, the problem that the Young Man had is the same problem Kierkegaard had with Regine Olsen. He had proposed to her, she had accepted but he had changed his mind. Kierkegaard was accused of "experimenting with the affections of his fiancée". Charles K. Bellinger says Either/Or, Fear and Trembling and Repetition are works of fiction, "novelistic" in character; they focus on the boundaries between different spheres of existence, such as the aesthetic and the ethical, and the ethical and the religious; they often focus on the subject of marriage; they can be traced back to Kierkegaard's relationship with Regine." There is much in this work that is autobiographical in nature. How much is left up to the reader. Kierkegaard explores the conscious choices this Young Man makes. He had written about repetition previously in his unpublished book Johannes Climacus. Kierkegaard published Fear and Trembling, Three Upbuilding Discourses, 1843 and Repetition all on the same date, October 16, 1843. Abraham was the main character in Fear and Trembling and the Three Upbuilding Discourses were about love. Repetition presents a noticeable contrast between the other two books that is almost comical. He takes up the idea of repetition again in his 1844 work The Concept of Anxiety where he explores the concepts of sin and guilt more directly. The book could be the counterpart of Goethe's Clavigo, which Kierkegaard dealt with in Either/Or. Structure Part One: Report by Constantin Constantius Part Two: Repetition Letters from the Young Man, August 15 – January 13 Incidental Observations by Constantin Constantius Letter from the Young Man, May 31 Concluding Letter by Constantin Constantius, Copenhagen, August 1843 Report by Constantin Constantius Constantin believes that "repetition and recollection are the same movement, except in opposite directions, for what is recollected has been, is repeated backward." An individual can remember some past event or emotional experience with intensity. That individual might try to "repeat pleasure continuously and eternalize the pleasure in