When asked what philosophy is for, Carlos Fernández Liria answers us with a paradox: for nothing and to govern. According to this book, the very thing about philosophy is that it serves nothing and yet precisely because Socrates and Plato was thought to serve to govern. Later, with the philosophy of the Enlightenment it was believed that this dream was about to come true, translating into a political model that, since the French Revolution, has been our most indispensable reference. The empire of reason is the attempt to bring the world to the height of truth, justice and beauty; three platonic ideas behind which lies a motto: "Freedom, Equality, Fraternity", with which a king was guillotined and the political spectrum of humanity was changed forever. Thus, after explaining how, now, we have returned to the Middle Ages, become servants of mad and tyrannical masters who call themselves "the markets", the author does not hesitate to say that, although philosophy had never contemplated such a defeat of his political aspirations, it remains essential to diagnose the gravity of what is happening and to present battle in the struggle ahead. The reader will find in this work an un technical explanation of the importance of philosophers and philosophy and their connection to the world in which we live.