In the literature of friendship -- which ranges from "We Have Been Friends Together" by Raissa Maritain to the ties between Thoreau and Emerson -- the name of James Flye has an honored place. He has been known as Father Flye, as in the title of the minor classic, "Letters of James Agee to Father Flye."

On April 12 at the age of 100, the Episcopal priest and teacher died in Sewanee, Tenn. A man who served God and children for eight of his 10 decades had a joyful life of private rewards reserved only for the truest believers. The public reward was in being honored as the mentor-friend of James Agee, the journalist, novelist, poet and user of pure English who died in a New York taxicab 30 years ago next month.

The letters between the priest and writer were published in 1962, with a second edition in 1971. The second is the fuller. It carries, as the first did not, some of the letters that Flye wrote to Agee. The years of correspondence run from 1925 to 1955, beginning with a youthfully exuberant note from Agee when he was a 15-year-old student in a New Hampshire boarding school and ending with a letter Agee wrote the last week of his life.

By then, he was the author of "A Death in the Family" and "Let Us Now Praise Famous Men," two works of lyrical prose that are still read for the emotional power with which they were written. Agee produced articles, poems and reviews -- for Time, Fortune, The Nation -- in a profusiveness that at times appeared to be a wild dispersal of talent. It reflected his personal life: restlessness that carried him undisciplined through several marriages, jobs, illnesses and unrealized dreams. His tie of friendship to Father Flye was a creative activity, like all the others, except it stayed grounded as if the intensity of feeling had a life of its own.

The two had met in 1918 when Father Flye was teaching at St. Andrew's School in Sewanee and Agee, 9, was in the fourth grade. For teachers, blessings to students are easy. Endorsements are harder. Father Flye, seeing gifts of the imagination in the child, was to lead him on, until one day, in a letter in 1939, he wrote to Agee: "Your writing moves me deeply, and you realize I say this quite objectively. So far as I can see, my feelings about a person -- liking, or great love, or great dislike -- do not enter, or at least exceedingly little, into my judgment of the literary worth of something written by that person. Besides what seems to me great beauty and clarity of language, I feel in your work a depth, a penetration far below the superficial, a sincerity, a keenness of sympathy, which move me very much. I am deeply interested in anything you ever write."

Agee rejoiced in this. The vitality he put into his letters was an extension of his insatiable love of writing. Few letters to Father Flye are without mention of it. From Harvard at 21, he confided that "from now on [I'm] committed to writing with a horrible definiteness . . . I'm thinking about it every minute . . . I'd do anything on earth to become a really great writer . . . I've got to strengthen those segments of my talent which are naturally weak."

As a man whose own calling was linked with a sense of vocation, Father Flye saw that in Agee. This would be no sterile life given over to the uselessness of making money or making waves. Heights would be reached, as well as depths. Once Agee ending a letter by calling it "lousy, a mouthful of sweet potato. I realized I've said virtually nothing about myself. Maybe that is a virtue in the Art of Letter-writing, but between friends it seems a vice, I have nothing good to say about myself."

When seeing his younger friend trapped in feelings of self-worthlessness, Father Flye, in the style of a confessor who understands that sometimes the wayward need to be comforted more than rebuked, responded: "When I think of the difference and opposition between those who have a sense of reverence, wonder and worship and those who do not; the cruel and the compassionate; those who yearn toward good and love and those to whom evil and ill-will are all too congenial; there is no doubt on which side you are."

Agee usually ended his letters with "my love to you always." He called Father Flye "my oldest and dearest friend." The pleasure of the correspondence was in the relaxed sharing of ideas about writing, books, God's mercy and providence. Each knew that sustained friendships are rare. They are often more demanding than marriage because there is no taking the other person for granted as years roll on. In a friendship the other must always be taken -- and cherished -- whole.

That may not seem much to ask, but not many achieve it. And fewer still fill it with as much grace as did this priest and writer, co-endorsers of each other.