Shortly after midnight on Christmas, Father Reginald Foster, papal Latinist for 40 years and the world's foremost Latin teacher, died at the age of 81 at St. Anne's Home in Milwaukee.

I had the privilege to be his student for four years in Rome, from 1995-99. While some of the great teachers I've had in life because of the subject matter -- like moral theology -- have had a more life-changing impact on me, Father Foster, or "Reggie" as he wanted to be called, was without a doubt my greatest classroom teacher. He took what in many places is an arid subject and made it absolutely enthralling -- and did so in the early afternoons, when the sleep-inducing insulin spikes of big Italian lunches were at their strongest. He was infectiously entertaining, funny, and eccentric, with a comedian's sense of timing and perspective coupled to 2,000 years of Latin humor.

By the time I had him, I had already had many years of Latin, but the opportunity to study with someone who had the reputation for being the "best" was irresistible. He was so much better, however, than I had imagined the best would be.

A true genius, he blew up the pedagogies of the way Latin is taught almost anywhere else, with a focus on grammar and the memorization of the conjugations of verbs and the declensions of nouns and adjectives. He turned Latin into a mystagogical experience, learning it from day one from great Latin texts, culled from Cicero and Ovid, from St. Leo the Great and St. Augustine, from inscriptions on monuments in Rome and liturgical texts. He had us, with him, jump into the full vitality of a living language and in so doing not only helped us learn the language the way those who spoke Latin in former centuries would have picked it up as children, but also brought us into conversation with some of the great thoughts of the greatest minds in history.

Reggie was convinced that one of the reasons why Latin was dying was because of the way it was taught: as an intimidating, difficult, almost cryptographic autopsy of dead texts. He reminded us that even dogs used to understand Latin commands and that ancient "bums and prostitutes" spoke it just fine. He sought to unite us in a shared love of the language, having us sign a "contract" at the beginning of class affirming our intention to be there because we wanted to learn the language, and not because we needed it to fulfill a requirement or at the recommendation of someone else. He would get into trouble with the authorities at the Gregorian University for allowing scores of Latin loving auditors to attend without inscribing as well as for saying to those students who were only there to meet a requirement that he would give the passing grade provided that they didn't take up space in the classroom and waste their, his, and everyone's time. He was certainly one of a kind.

The sheer amount of time and effort he would give to students was incredible. He had a full-time job for 40 years in the Latin Letters section at the Secretariat of State in the Vatican, which required not only translating all of the major documents of the Church into their definitive Latin versions but also composing in Latin many of the official letters of the pope for episcopal appointments, expressions of condolence, greetings to heads of state or government and so on. After that work completed, he would then teach every afternoon two different 90-minute classes, spread over five different "experiences," from the first (beginners) to the fifth (advanced), each of which meeting twice a week. In any given year, he would have 180-200 students. He would learn every student's name as well as the student's strengths and weaknesses. He would compose on a typewriter new homework every year for each of the five experiences -- called "ludi domestici" or "home games" -- and painstakingly correct it himself, with multicolored pens, something that would take him, on average, about six hours a day.

Then there would be the field trips, to where Julius Caesar was killed on the Ides of March, to the Roman Forum, to the obelisks of Rome, to the Roman port of Ostia Antica, to Cicero's hometown, to Thomas Aquinas' place of birth and death, to Tiberius' cave and more. For each, he would prepare packets full of Latin texts about what we would be learning and the sites became like the laboratory of the living language. For the trips outside of Rome, depending upon the number, we would have meals that Reggie himself would largely pay for, looking at the bill and then suggesting that each of us owed a small divided portion with his paying the rest.

After I finished my studies, I stayed in touch with Reggie. I would visit with him at least once a year when I would be in Rome. We would generally meet for breakfast at a café just outside St. Peter's Square, where we would catch up and have a lot of laughs. I'll never forget at one of these breakfasts he looked like he was about to burst from holding a secret. "What's got you so upbeat?," I asked. "Lucis mysteria!" he replied. "Mysteries of Light. What does that mean?," I asked. He mentioned that the following day Pope John Paul II would be publishing an exhortation on the rosary -- Reggie had just finished with the Latin translation -- and it would include a new set of the luminous mysteries. Every time I pray the Mysteries of Light I remember Reggie.

After 2009, when he retired from the Vatican and returned to Milwaukee to deal with a series of serious health issues -- and where he would continue to receive students and teach -- we would exchange letters and cards a couple of times a year. Whenever I wrote him, even at the risk of being a broken record, I would thank him for his passing onto me the treasure of far greater facility in the Latin language and his infectious love for it. Whenever he wrote me, he was so positive and encouraging, talking about the students with which God was still blessing him, commenting upon some article or television appearance he had seen of me, and in general just expressing his gratitude for life and for everything. One particularly touching card was when he found out I had been appointed a papal Missionary of Mercy and he penned a beautiful postcard in Latin describing the importance of Christ's mercy. Most of his cards would start, "Rogerio suo plurimam ipse Reginaldus salutem" ("Reggie wishes Roger much health!") and would finish, "Frater Carissime, Roger, Vale!" ("Goodbye, dearest brother Roger").

One of the things Reggie's students -- especially seminarians, priests and religious -- needed to confront when taking his classes was his occasionally scandalous behavior. He was anti-authoritarian and disobedient. He would dress basically in a blue janitor's outfit from JC Penny rather than his Carmelite habit. He asked to be called Reggie rather than Father. He would take beer or wine into the classroom and drink while teaching. He would say some highly tendentious things with regard to Church teaching in the classroom and in interviews.

Most of us were prepared for it before entering his classes and so we were not shocked -- and just numbered it among his eccentricities. But as I observed him more carefully over the years and talked with him about it, I became convinced that most of that involved inappropriate overreactions to sound spiritual insights. While an intellectual genius, Reggie always struck me as emotionally in a state of rebellion against the scrupulosity of teens, a rigid formation system when young men could get booted from seminary for reading the Bible after lights out or taking a puff of a cigarette, and the corruption he saw up close later as a priest in the late 60s and 70s and in his work in the Vatican. Most of his outlandish behavior and renegade comments flowed, I think, from an essentialism with regard to the faith that led him to criticize less important things for the sake of the more important.

He would, for example, occasionally criticize the popes, but when pushed he'd say things like, "How can everybody say, 'Viva il papa!' when he processes down the nave at St. Peter's, when everyone ignores Jesus in the tabernacle?" He would criticize bishops, but when pushed, he'd say, "How can they casually close churches when Jesus Christ dwelled there for a hundred years!" He'd note that the Bible doesn't say anything about contraception, but when pushed, he would say, "How can certain churchmen hold married couples to a high standard when they aren't holding themselves to high standards?" Reggie's statements seemed to be adolescent pulling of fire alarms that underneath often showed real faith, the faith that got him up every day at 3:58 a.m. to celebrate Mass, the faith that got him to share his food with the poor throughout Rome.

Once when we were having lunch on a field trip to Arpino, a lay student asked Reggie about euthanasia. Reggie said that if he got old and sick, he would just row out into the middle of lake, tie a cinderblock around his neck and that would be the end of it. I challenged him on it, saying that he would never do that, because it would violate everything he stood for. "Don't hit me with Church teaching! That doesn't matter," he retorted. I told him we both know it does, but that the reason why he wouldn't do it is because his love for his students was like Mother Teresa's love for the poor and he would never rob his students of the chance to give back to him a little for what he had given to us, if he should be in need. A tear began to roll down his cheek. He conceded, "I suppose your right." The students applauded. I lifted my glass and said, "In vino, veritas!" He smiled and said, "Ita!" "That's right."

His iconoclastic bombast always struck me as being an inappropriate protest against things he didn't like in the ways certain truths were taught or by whom they were taught. In depth, I thought Reggie remained the young boy who would make vestments out of bed sheets to practice Mass, who from his earliest days wanted to be a priest, a Carmelite and do Latin.

I like to believe it was a sign from God in response to Reggie's childlike faith that the Lord came for him on Christmas at the time when the angels were singing to the Shepherds "Gloria in excelsis!" Once I sang the Gloria with Reggie at the first Mass of a mutual friend who, after being ordained in the States, flew to Rome to celebrate his first Mass at St. Mary Major Basilica. The priest, Reggie and I were the only three present before the image of Mary "Salus Populi Romani." Reggie told the newly ordained Father James Mercy that he and I would be the choir and we sang everything in Latin, with Reggie singing with gusto from memory the "De Angelis" Mass parts, Marian Hymns, the "Veni Sancte Spiritus" (it was Pentecost) and a "Te Deum." Reggie's zealous love for God, for the Mass, for the priesthood, for our Lady, and for his students all came out in an unforgettable way.

When Reggie himself would celebrate Mass, he would always devoutly stress the "meum" (my) in the "This is my body" and "This is the chalice of my blood." It was a sign of how closely he sought to identify with Christ. That, to me, was always the "real" Reggie, notwithstanding the public impiety he would occasionally evince.

I pray that that internal configuration to Christ in the new and eternal Passover, that love for Our Lady, that zeal for God will be his ultimate earthly valedictory and the main subject of his Christmas conversation with the "Magister," "Salvator," and "Iudex" whom he held in his hands each morning and whom we pray now embraces him with similar love forever.

- Father Roger J. Landry is a priest of the Diocese of Fall River, Massachusetts, who works for the Holy See's Permanent Observer Mission to the United Nations.