This is the fundamental work that helps us to understand a council that lasted more than 50 years. Studying the Second Vatican Council, as we know, is not easy: its reception is still ongoing and we must be aware of it. The work of Melloni allows us to focus the matter in a better way, being aware that who was studying the Council at the end of the 20th century and who is studying it in the first decades of the new century, is still studying something that changes every time.