Julie or the New Heloise (French: Julie ou la nouvelle Héloïse), originally entitled Lettres de Deux Amans, Habitans d'une petite Ville au pied des Alpes ("Letters from two lovers, living in a small town at the foot of the Alps"), is an epistolary novel by Jean-Jacques Rousseau, published in 1761 by Marc-Michel Rey in Amsterdam. The novel's subtitle points to the history of Héloïse d'Argenteuil and Peter Abélard, a medieval story of passion and Christian renunciation.

The plot, entirely related through letters, turns on the spontaneous love between Julie d'Étanges, an aristocratic Swiss maiden living in Vevey on Lac Léman, and her tutor, a commoner who has no name but is given the pseudo-saint's name of St. Preux by Julie and her principal confidante, her cousin Claire. Although Rousseau wrote the work as a novel, a philosophical theory about virtue and authenticity permeates it. A common interpretation is that Rousseau valued the ethics of authenticity over rational moral principles, as he illustrates the principle that one should do what is imposed upon oneself by society only insofar as it would seem congruent with one's inner principles and feelings, being constituent of one's core identity. As this stood in conflict with the Church's authority, the book was listed on the Index Librorum Prohibitorum, prohibiting its distribution to Catholics.^[1]

Arthur Schopenhauer called Julie one of the four greatest novels ever written, along with Tristram Shandy, Wilhelm Meister's Apprenticeship and Don Quixote.^[2] Julie's eventual husband, the virtuous atheist Baron de Wolmar, is assumed to be based largely on Baron d'Holbach, given his friendship and generous sponsorship of Rousseau.^[3]

Julie was perhaps the best-selling novel of the 18th century.^[4] Some readers were so overcome that they wrote to Rousseau in droves, creating the first celebrity author. One reader claimed that the novel nearly drove him mad from excess of feeling while another claimed that the violent sobbing he underwent cured his cold. Reader after reader describes their "tears", "sighs", "torments" and "ecstasies" to Rousseau.^[5] Diane de Polignac wrote to Marie Madeleine de Brémond d’Ars after finishing the novel:

I dare not tell you the effect it had on me; no, I was past weeping; an intense pain took possession of me, my heart seized up; the dying Julie was no longer someone unknown to me, I became her sister, her friend, her Claire; I was so convulsed that had I not put the book down I would have been as overcome as all those who attended that virtuous woman in her last moments.^[6]

Some readers simply could not accept that the book was fiction. Madame Duverger wrote to Rousseau asking:

Many persons who have read your book, to whom I have spoken, have assured me that you thought it all up. This I cannot believe. Could a false reading n sensation comparable to what I felt in reading it? Once more, Monsieur, did Julie exist? Is St Preux still alive? In what part of this earth does he live? Did Claire, that tender Claire, follow her other half? Are M. de Wolmar, Mylord Edward, all those persons, only imaginary, as some try to persuade me? What is then the world where we live, where virtue is but an idea? Happy mortal, you alone perhaps know and practice it.^[7]

Others identified less with the individual characters and more with the nature of their struggles, seeing in Julie a story of temptation, sin and redemption that resembled their own lives.

Rousseau liked to tell of how one lady ordered her carriage to take her to the Opera, and then picked up Julie only to continue reading it until the next morning. So many women wrote to him offering their love that he speculated there was not a single high society woman with whom he could not have bedded if he wanted to.^[8]

• Public opinion
• Bibliotherapy – Form of psychotherapy involving reading