David M. Perry: Echoes of Past in Pope's Resignation

David M. Perry is an associate professor of history at Dominican University in River Forest, Illinois.

(CNN) -- On July 4, 2010, Pope Benedict XVI traveled to Sulmona for his second visit to venerate the relics of his long-ago predecessor, Pope and St. Celestine V, who died in 1296. Few predicted then that just a few years later, Benedict and Celestine would be locked together in history as the two popes who retired, theoretically voluntarily, because of their age.

Here is what Celestine wrote: "We, Celestine, Pope V, moved by legitimate reasons, that is to say for the sake of humility, of a better life and an unspotted conscience, of weakness of body and of want of knowledge, the malignity of the people, and personal infirmity, to recover the tranquility and consolation of our former life, do freely and voluntarily resign the pontificate."

Compare that to Benedict's statement: "In today's world, subject to so many rapid changes and shaken by questions of deep relevance for the life of faith, in order to govern the bark of Saint Peter and proclaim the Gospel, both strength of mind and body are necessary, strength which in the last few months, has deteriorated in me to the extent that I have had to recognize my incapacity to adequately fulfill the ministry entrusted to me. For this reason, and well aware of the seriousness of this act, with full freedom I declare that I renounce the ministry of Bishop of Rome, Successor of Saint Peter."...