Abstract
The aim of this article is to examine whether the moral universalism of the Enlightenment is incompatible with the multiculturalism of the societies of the 21st century. That leads to study what the moral universalism of the Enlightenment was. Under the guiding hand of Habermas, the article uses a distinction between the procedural- formal project of the Enlightenment and the particular contents in order to highlight that the most important thing was the project and that the freedom of being different was at the heart of this project. This freedom was one of the most important values which the Enlightenment wanted to broaden, so not only is moral universalism compatible with cultural diversity but what makes it possible. Then the article considers two of the most important ways of understanding the multiculturalism, the points of view of Habermas and Appiah, to end up showing that even some of the most passionate defenders of multiculturalism, like Appiah or Parekh, admit that some universal moral values are essential for a multicultural world