This book attempts an introduction to a very beautiful and complex poem written in Portuguese by Luís de Camões in the latter part of the sixteenth century. The poem, which has no authorial title, is sometimes called Sôbolos rios (after its incipit) or Babel e Sião (“Babylon and Jerusalem”) after the binary images around which it is constructed. As neither Portuguese literature nor sixteenth-century poetry has been a prominent subject of my earlier published work, I perhaps owe my reader some explanation of how the book has come about. Humanistic study, at least in my experience, is seldom linear. Much more often it is erratic in the old Latin sense that suggests digression and divagation, a wandering from one's original, ideal perception of a broad, straight path to explore the byways, and then the little lanes and alleys into which they branch. A great deal of my own long scholarly life has been taken up with exploring things that I came to believe, in the course of pursuing some original intention to which I had committed myself, were preliminary necessities to its achievement.

One of the subjects on which I have expended scholarly energy in the past is the history of the Franciscan movement in the Middle Ages. (This topic, incidentally, began in digression. I was trying to understand the “background” to the antimendicant satire prominent in such important vernacular poets as Jean de Meun and Geoffrey Chaucer.) The Franciscan Order, which played such a major role in the religious life of late medieval Europe, was destined to play a major role in the religious history of the Americas as well. Christopher Columbus himself was animated by a number of distinctively Franciscan ideas and attitudes. Some public lectures I gave on this topic indirectly led to an invitation to serve as one of the guest curators of a major public exhibition at the Library of Congress (“The Continuing Voyage”) marking the Columbian Quincentenary in 1992.

The experience was pleasant and memorable, but the task presented me with a considerable challenge as well as an opportunity, for I felt obliged to undertake an extensive course of reading in a number of large subjects concerning which I knew very little.