Heidi is an old-fashioned book in which the good characters live "happily ever after." In today's uncertain world, where both the news and fiction tend to be painfully realistic, it is reassuring to find a story where good people are rewarded and where love and honesty triumph. Modern readers may find certain aspects of the book a bit overdone. Heidi is almost too full of joy, Peter too simple-minded, and the grandfather too all-knowing and kind beneath his gruff exterior to be totally believable. Yet readers care about these characters deeply and become much involved in their story.
The book was originally written in German and first published in English in 1884. It is a simple narrative of love between a girl and her grandfather, of the joy of helping others, of the beauty of nature, and of reverence for God. Neither of the villains, the selfish Aunt Dete and the pretentious Fraulein Rottenmeier, can appreciate the natural goodness of Heidi, the girl of the mountains. Heidi's home in the Alps is an idyllic place, far from the modern world and its concerns. The enduring popularity of the book arises from the liveliness of its characters and the universality of its themes. As Clifton Fadiman observes in his afterword to the Macmillan Classics edition of Heidi, ever since that first English translation in 1884, "year after year, it has kept its place in the hearts of young readers, especially girls." At present, there are fifteen editions in print, three of them in simplified versions. The secret of its continued success is simply that Heidi makes its readers happy.