"Human beings, though part of this cosmos, transcend it", he said. "Of course man always remains man in all his dignity, even if in a coma or in the embryonic state, yet if he lives only biologically he does not realise and develop all the potential of his being. Man is called to open himself to new dimensions".
The first dimension, said the Pope, is that of knowledge. In this context he noted how, unlike the animals, "man wishes to know everything, all of reality. ... He thirsts for knowledge of the infinite, he wishes to arrive at the font of life and to drink therefrom, to find life itself".
This, he continued, leads to the second dimension: "Man is not just a being who knows, he also lives in relationships of friendship and of love. Beyond the dimension of knowledge of truth and of being, there also exists, inseparable from it, the dimension of relationships, of love. And it is here that man comes close to the source of life from which he wishes to drink in order to have life in abundance, to have life itself".
Science, and medicine in particular, he went on, "are a great struggle for life", yet even if medicine were to find "the prescription against death, the prescription of immortality" it would still "be confined within this biosphere.
"It is easy to imagine what would happen if man's biological life were endless, if he were immortal", the Holy Father added. "We would find ourselves in an aged world, a world full of old people, a world that would leave no space for the young, for the renewal of life. Thus we understand that this cannot be the kind of immortality to which we aspire. ... Drinking from the font of life is to enter into communion with this infinite love which is the source of life".
After recalling how the Fathers of the Church called the Eucharist "medicine of immortality" , Benedict XVI explained that in this Sacrament "we enter into communion with the body [of Christ] which is animated by immortal life and thus we enter, now and always, into the space of life itself".