From the address personally written by Pope Benedict for his previously scheduled visit to the University of Rome - la Sapienza (partial translation by AsiaNews):
The pope is, first of all, the bishop of Rome, and as such, in virtue of apostolic succession from the Apostle Peter, he has episcopal responsibility in regard to the entire Catholic Church. The word "bishop" - episkopos, which in its immediate meaning refers to "supervision", already in the New Testament was fused together with the biblical concept of the shepherd: he is the one who, from an elevated point of observation, surveys the whole landscape, making sure to keep the flock together and on the right path. This description of the bishop's role directs the view first of all to within the community of believers.
The bishop - the shepherd - is the man who takes care of this community, the one who keeps it united by keeping it on the path toward God, which Jesus points out through the Christian faith - and He does not only point this out: He himself is the way for us. But this community that the bishop cares for - as large or small as it may be - lives in the world; its conditions, its journey, its example, and its words inevitably influence the rest of the human community in its entirety. The larger it is, the more its good condition or eventual decline will impact all of humanity. Today we see very clearly how the situation of the religions and the situation of the Church - its crises and renewals - act upon the whole of humanity. Thus the pope, precisely as the shepherd of his community, has increasingly become a voice of the ethical reasoning of humanity.
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The purpose of knowing the truth is to know what is good. This is also the sense of Socrates’ way of questioning: What good thing makes us true? Truth makes us good and goodness is true. This optimism dwells in the Christian faith because it was allowed to see the Logos, the creative Reason that, in God’s incarnation, revealed itself as that which is Good, as Goodness itself.
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If ...reason, concerned about its supposed purity, fails to hear the great message that comes from the Christian faith and the understanding it brings, it will dry up like a tree with roots cut off from the water that gives it life. It will lose the courage needed to find the truth and thus become small rather than great. Applied to our European culture this means that if it wants to constitute itself on the basis of its arguments and whatever appears to it to be convincing, with concerns about its own secular nature, it will cut itself off from its life-sustaining roots, and in doing so will not become more reasonable and pure but will instead become undone and fragmented.
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What does the Pope have to do or say in a university? He certainly should not try to impose in an authoritarian manner his faith on others, which can only be freely offered. Beyond his ministry as Pastor of the Church and on the basis of the intrinsic nature of this pastoral ministry, it is his task to keep alive man’s responsiveness to the truth. Similarly he must again and always invite reason to seek out truth, goodness and God, and on this path urge it to see the useful lights that emerged during the history of the Christian faith and perceive Jesus Christ as the light that illuminates history and helps find the way towards the future.