One of the most jarring aspects of Benedict's resignation is that it occasions a circumstance that has not been seen since 1400s: a new pontificate coexisting with the previous pontiff. What we are to witness on February 28th is a situation totally foreign to the modern expectations of papal transition. Benedict XVI's assumption of the papal throne was occasioned by the great fanfare and outpouring of devotion in memory of his predecessor, John Paul II. This time, the transition to a new pontiff will provide no such opportunity - a major component in the ritual process of transitioning to a new pope will thus not be in place. Naturally, one wonders if Pope Benedict will be entirely passive during the pontificate of his successor or if he will be in the wings with some hand involved in the process. Remember, Ratzinger was powerful cardinal, as much a force in John Paul II's papacy as the deceased pontiff himself. If Benedict is intent upon walking into the sunset, then the new pontiff will likely have space build his papacy as he sees fit. However, Benedict is an intellectual force and he still has his network of loyalists in place within the halls of Vatican. It is therefore not inconceivable that Benedict could exert some influence in the next pontificate, either by his own volition or under appeal from his intellectual devotees.
Then again, Benedict may genuinely wish to retreat from the mechanics of the Roman Church. Joseph Ratzinger undoubtedly had a profound vision for the Roman Church. One can read his masterwork, Introduction to Christianity, and readily see that he has a vision for the Christian kergyma in the wake of Modernity. When promoted to head of the CDF, Benedict's intellectual vision, which was so often sweeping in scope and challenging of enshrined aspects of Catholicism, was brought into conflict with the clearly defined role of his new office - a position he railed against during the Second Vatican Council. This tension was brought into view once again while pontiff. Reading the volumes of Benedict's treatment of Jesus of Nazareth, one sees, if one reads the text closely, another rift between the theology of Joseph Ratzinger and the demands of his position as Roman pontiff. Indeed, the conflict between Ratzinger and the restrictions of the papacy came out in many venues. I recall during the first few months of his pontificate, Benedict entertained the idea of revisiting the Church's prohibition on divorced and remarried persons receiving communion on the grounds that it is very much possible that, for whatever reason, such persons could not comprehend the nature of the sacrament they were participating in and only later, through their new relationship, understood the sacramental nature of marriage. The mercy of God, it would seem, would permit full communion. This statement by the pope made no headway during his pontificate. One can also review the two year long build up to the release of his social encyclical, Caritas in Veritate. Benedict's personal remarks on the intention of the document (going so far as to say the document would focus on the incompatibility of serving God and Mammon) were a far cry from what was eventually released. For months leading up to the document's release, Benedict sounded a critical tone with regard to the global financial system and economy. Caritas in Veritate was, at best, a plea for the system to act humanly and devoid of any systematic critique. Let's not forget that the last two years of Benedict's pontificate were marred by the resurgence of the sexual abuse scandal and the deep divisions within the Vatican (some hostile to Benedict himself) as revealed by the "Vatileaks" documents.
As a theologian, Joseph Ratzinger developed a theology that had much promise for Catholicism. As pontiff, Benedict began his pontificate with promise. In both roles, the grind of the Vatican machinery proved unstoppable. I challenge anyone to review the first six or so months of Benedict's pontificate. Review every audience and address, read those texts carefully. Compare the vision of Benedict's first months with the direction that eventually established itself as the norm for this papacy. Benedict has, to a certain degree, watched his theological vision constantly be eclipsed by the Church's institutional pressure and obligations and the last two or so years have been marked by ever increasing fissures caused by a profound institutional crisis. Benedict has proven unable to manage the deficiencies that run deep in the Roman Church's structure, all of which seem to have risen in the last period of his papacy.
It may well be Pope Benedict XVI proves most comparable to Pope Celestine, the medieval hermit who was elected pontiff and resigned after encountering institutional largess of the Roman Church. Celestine was vilified immediately, however, history has proven sympathetic to Celestine's rejection of the Church's institutional apparatus and decision to resign as pontiff. When the polemics surrounding Benedict's papacy have cleared, when both his supporters and detractors commit themselves to a thorough reading of his writings, I suspect Benedict will be seen as having been ultimately unable to cope with the Roman Church's institutional girth. Joseph Ratzinger's theology was never suited to institutional process; it is not an intellectual exercise for him, it is the means by which he understands reality, visible and invisible. I suspect that Benedict, like Celestine, simply had enough with the superstructure of the Roman Church.