The concept of the West, although constantly present in every discussion of culture or geopolitics, remains vague and problematic. This is exactly the concept that Philippe Nemo tries to define in this book, based on history. According to the author, in order for what we now call the West to be formed, five crucial historical moments collaborated:
- the invention of the city and science in Ancient Greece
- Roman private law and humanism
- the ethical and eschatological prophecy of the Bible
- the "papal revolution" (11th-13th century), which established human action
- the great democratic revolutions of modern times.

These five key moments, the five "evolutionary leaps," as the author calls them, radically changed the relationship between humans and nature, the past and future, and other humans, ultimately shaping the current cultural and political profile of the West.

In this historical moment, contrary to the advocates of cultural mixing, Philippe Nemo proposes the defense of Western identity, the political and cultural borders of the West, in an always open dialogue with other cultures.