The purpose of this book is to serve as a map and compass. We will try to explain the radical social and intellectual change that has taken place between the twentieth century - in an important sense, the century of Marxism - and the twenty-first century, a process of change that began in the period between 1978 and 1991, when China approached the market economy and the Soviet system collapsed in Europe and in the USSR itself. This study does not aspire to trace an intellectual history or a history of ideas, but rather should be considered as a travel notebook, a set of unpretentious notes gathered after an arduous and long journey through the ascents, descents and the paths without return of Marxism of the twentieth century and the early years of the twenty-first.
The book has two objectives. The first is to place political practice and leftist thinking of the early 21st century on the ground of the previous century. The second, in offering a systematic vision of leftist thinking in the northern hemisphere at the dawn of this new century, and comparing it with the Marxism of the preceding era.
Although I will try not to advocate a particular route or interpretation, I do not intend to hide that this is the work of a scholar who has not renounced his commitment to the left. In fact, it was precisely that commitment that prompted me to write this book.