Thomas Cahill is writing a series of popular (and profitable) books under the general title: "The Hinges of History." The latest handsome volume is  Mysteries of the Middle Ages.

Acknowledging one of his own sources, Norman Cantor's Inventing the Middle Ages, Cahill calls it "selective, quirky, and subjective." If I may make bold: the same assessment seems applicable to Cahill's own volume.

Yet, I forgave him all his excesses, di tutto cuore, when I came upon his description of the mosaic of the Cross as Tree of Life in San Clemente. He writes: "[it] presents us with a view of reality that is both cosmic and eucharistic ... there is no sight in all of Rome more worthy of contemplation." E troppo vero!

Cahill ends his reflection (enhanced by wonderful photos) with these words:

To appreciate the impact of this mosaic it is nearly necessary to attend a Mass celebrated at the altar below the apse. As the ritual of the Mass unfolds beneath the cosmic wildness of the apse, we reflect that we are all caught up in the universal mystery of Christ, who has redeemed us and all of creation, even the humblest humans and the humblest things, so that he might come to us as bread.

When I sit, contemplating the mosaic during the celebration of the Eucharist, I sense the presence of countless pilgrims who, through the ages, have been strengthened in their love of Christ by this masterwork of anonymous artists of centuries past.

I wonder whether Francis of Assisi paused here for prayer on his way to the nearby Lateran Palace and his history-changing encounter with Innocent III. I muse that perhaps Thomas Aquinas composed his great Sequence Adoro Te Devote while kneeling before the life-giving Cross. If not the whole Sequence, surely the fifth stanza:

O memoriale mortis Domini
          panis vivus
vitam praestans homini,
praesta meae menti de te vivere
et te illi semper dulce sapere.

A blessed celebration of the Holy Triduum in which Jesus the Christ recapitulates all things in himself, becoming Eucharist for the many, for all.