On balance, I'd have to count myself a fan of Eugenio Pacelli, better known to the world as Pius XII. Pope Benedict celebrated a mass this week on the 50th anniversary of Pius's death, an event that led to some controversy due to the ongoing debate about Pius' actions during World War II.My interest in Pius stems from three very important encyclicals he wrote during the course of his pontificate. The first, Divino Afflante Spiritu (1943), was a breakthrough moment for the modern biblical movement within the Catholic Church. In the early part of the 20th century, the attitude of the Church toward modern biblical criticism was strongly negative. While there were certainly reasons to be concerned about some of the more skeptical trends in modern exegesis, I think is generally accepted that the Church overreacted. Pius' encyclical gave Catholic biblical scholars more freedom to pursue their work and laid the groundwork for Vatican II's document Dei Verbum.The second, Mystici Corporis (1943), articulated a vision of the Church as the "mystical body of Christ." This was an understanding of the Church that, while rooted in Scripture, had been gradually recovered by theologians, clergy and the laity since the 19th century. It was popularized in this country by individuals like Archbishop Fulton Sheen among others. This ecclesiology laid the groundwork for progress in the ecumenical sphere and a new appreciation of the role of the laity. Many of the ideas contained in Mystici Corporis reappear in Vatican II's Dogmatic Constitution on the Church, Lumen Gentium. The third, Mediator Dei (1948), was a cautious endorsement of the goals of the Liturgical Movement, which had been gaining support among clergy and laity in northern Europe and to a lesser extent North America. The encyclical endorsed the goal of encouraging the active participation of the faithful in the celebration of the liturgy and allowed for the use of the vernacular in the celebration of the sacraments. Mediator Dei validated the efforts of those involved in liturgical movement and paved the way for the liturgical reforms of Vatican II.When we think of the popes of the Second Vatican Council, we usually think of John XXIII and Paul VI. I would argue, though, that without Pius XII, there would probably not have been a Council, not least because it was Pius who made Angelo Roncalli the Patriarch of Venice and a Cardinal! More fundamentally, though, it was Pius who first endorsed a cautious opening of the Church to many of the most important theological, liturgical, and biblical trends of the modern period.It seems that no reflection on Pius can be complete without an assessment of his actions during World War II. But I don't think I can adequately address that issue here. I think it is fair to say that no one during that period did enough to save Jews from the Holocaust. If I had to make a list of prominent individuals in those years whose failure to act was morally culpable, I'm not sure that Pius would be in the top ten. But I will leave that debate for another time.