On September 11, 2001, two planes crashed into the Twin Towers, destroying them in their entirety. The attack, inspired by religious fanaticism, killed nearly 3,000 people and injured another 6,000, as well as destroying the area surrounding the World Trade Center in New York. The century was off to a bad start. Things are no better in Iraq these days. Thirty-three days after the 9/11 attack, Jürgen Habermas received the national booksellers' award in Frankfurt's Pauluskirche with the utopian motif of peace. Contrary to the dominant voices that spoke of new wars of religion, the enlightened philosopher and neo-Marxist ("with little musical ear for religion," as he himself said) affirmed that the attack "had struck a religious chord in the innermost part of secular society. Churches, synagogues and mosques were filled, and not to cry out for revenge. Moreover, he claimed that fundamentalism was a modern phenomenon, which owed more to ideologies than to religious principles (in this he agreed with Ratzinger, who thought that Islamic fundamentalism owed more to Marxism than to Islam). Habermas further argued that the ethical foundations of the liberal state were of religious origin, albeit secularized and expressed in a rational sense.

Two and a half years after the attack on the Twin Towers, in 2004, the famous meeting took place between Habermas and Ratzinger, the enlightened philosopher and the dogmatic theologian, which gave rise to the so-called Munich Paper. It is now ten years since that discussion. First of all, the degree scroll of the speech is significant: "Pre-political moral foundations of the liberal state". Thus, a liberal society is understood as a possible space for coexistence, i.e., a democratic and pluralistic society; we are not thinking of a confessional State, or of an identification between Church and State. Secondly, we speak of "pre-political moral foundations": we are not going to speak of politics or of a particular ideological orientation, but of ethics and of the prior foundation of the political game, according to the principles emanating from Christian thought. There was thus an initial harmony between the two interlocutors.

Far from Pilate's skeptical and contemptuous question ("what is truth"), Ratzinger and Habermas were both serious about the "question of truth," perhaps from different perspectives. In this sense, the future Pope appealed to the "project of a world ethic" (Project Weltethos), for which Hans Küng had advocated, but to which he would give a new content. A world ethic must be possible that could be shared by all, believers and non-believers, all thinking people. Ratzinger relied more on reason and science than on a Christian faith that is not always shared by all. He did not Withdrawal to it, but he did not impose it either. As Chesterton had said: the present problem is not so much that of the lack of faith, but that of the lack of reason?

Ratzinger also appealed to law, which must be above individual interests and "the law of the strongest. This law must be combined with freedom: in it it must be realized in a way plenary session of the Executive Council. Law is not an instrument of power, but "an expression of the common interest of all". For this reason, it cannot restrict or limit my freedom, but rather give it wings, help it to grow. Apart from the criterion of the majority, we need a reference letter common to all, a shelter in which all can take refuge. This is what we call truth, nature, human dignity or what Habermas boldly calls imago dei, perhaps in a weak sense. For even consensus is not sufficient as a basis for human rights, as can be seen today. It would be necessary to overcome the crisis of law or natural law, for all we care. 

The theologian Johann Baptist Metz considered that Habermas could not simply be considered a "postmetaphysical" philosopher, and at the same time mentioned the scandalous stone: the question of truth. The difference between the two was therefore clear: while for Habermas truth is the fruit of dialogue, for Ratzinger dialogue is the fruit of truth. While the philosopher understood truth only as consensus, for the theologian it is the truth that saves, incarnated in the person of Jesus Christ, to which we have access through reason. In the present circumstances of expansionist caliphates the question is not out of place. The question that remains open to us then is whether, in the midst of this postmodern and - we could say - post-secular environment, religion will have a place. At least, it would be enough for the moment if reason, conscience, justice and a broad concept of nature also had a place. The agreement reached by Habermas and Ratzinger ten years ago from the point of view of difference could shed some light on the present moment.