In 1399 Thomas, at Florens’s instance, decided to assume the monastic vows. A second house of the order had been established at Agnietenberg (or Mount St. Agnes) near the city of Zwolle. Of this John à Kempis had been made the second prior in 1398, and held that office until 1408. Thither Thomas proceeded in 1399, stopping at Zwolle to obtain the indulgence lately proclaimed by the Pope for the benefit of a new church in that city. After a novitiate of seven years he took the vows in 1406, and in 1414 was ordained to the priesthood.

The monastic life is studiously and intentionally monotonous. It aims at the exclusion of all that gives zest and interest to ordinary existence, and at the reduction of life’s employments to a routine. Its variety and color are to be sought in the inner life of its members, and that of Thomas was not wanting in these elements. If his inner experience be reflected in his Soliloquy of the Soul, he passed through those shifting seasons of gloom and gladness which characterize the experience of an introverted religion. His religious character was formed on the lines of the modern devotion, as defined by Gerard Groote, and as reflected in the lives and the writings of Florens Radewinzoon, Gerard Zerbolt, Johann Mande, Gerlach Peterszoon, and Johann Brinckerinck, the earlier notable men of the brotherhood or of the Windesheim congregation. His was not a bold and originative mind to strike out new paths for himself. He had not even those gifts of practical administration for which Florens, John à Kempis, and others of the order were notable. Even when he had attained recognition as the most eminent man at Agnietenberg, his brethren twice passed him by in selecting their prior, and never gave him any dignity higher than the sub-priorate, which probably was a sinecure. An early biographer goes so far as to describe him as sitting silent whenever ordinary and worldly matters were discussed, because of his ignorance of the very terms used at such times. But this is an exaggeration. His Chronicle of the Monastery of Mt. St. Agnes shows him taking a mild and not unintelligent interest in the secular side of the monastic life, and sharing the joy of his brethren in the fine apple-crop or the large take of fish, and the like. But this Chronicle shows how limited his range of vision and interest. He lived through the Papal Schism, the Asiatic conquests of Timour, the Council of Constance, the Hussite wars, Henry the Fifth’s invasion of France, the exploits of Jeanne d’Arc, the Council of Basle, the rise of the Medici in Florence, and of the Duchy of Burgundy, the Council of Florence, the exploits of Scanderberg and Hunyadi Janos, the Wars of the Roses, the revival of letters, the invention of printing, the fall of Constantinople, the Florentine Academy, the Portuguese discoveries in the Atlantic, and much more that might be thought likely to be discussed even within the walls of a Dutch monastery. But the record is silent as to all these things; for the most part they are part of the doings of that “world” which the disciples of the modern devotion trained themselves to despise.

No doubt the great question of the Papal Schism was of interest at Agnietenberg, and also the two great councils which brought it to an end. At the Council of Constance the Brethren of the Common Life were arraigned by a zealous Mendicant as violating Church law by observing the three rules of the monastic life without belonging to any recognized order. But this Mendicant notion was declared heretical, thanks to two great French doctors, Pierre d’Ailly and John Gerson, the second of whom was to be associated so closely with Thomas in a famous controversy.

In 1427 the troubles of the outside world did reach the convent at Agnietenberg and its associates. There had been a disputed election to the princely diocese of Utrecht, then one of the largest and wealthiest in Latin Christendom. The Pope recognized one candidate and the people of the cities another. To break down their obstinacy the diocese was laid under an interdict, which put an end to every act of public worship. Thereupon the brotherhood and the order were given their choice by the citizens, either to go on with their services as usual in church and chapel, or to leave the diocese. With one consent they chose the latter alternative, and in 1429 they distributed themselves among the associated brother-houses and monasteries outside the diocese. The twenty-four clerical and lay brethren of Agnietenberg found a home at Luvenkerk in Friesland, in a disordered monastery which had been placed under the rule of the Windesheim congregation, and which they used this opportunity to reform. After three years of exile they were allowed to return, a new Pope having yielded to the people. But Thomas did not return so soon, for he had been called away to Arnheim to the death-bed of his brother John, the brother he had found at Windesheim instead of Deventer, and under whose priorship at Agnietenberg he took the vows.

In 1451 Deventer was visited by a great Churchman and notable thinker, the Cardinal Nicolas of Cusa, who, like Thomas, was born east of what is now the German frontier, but had received his schooling in Deventer, where he learned to love and honor the Brethren of the Common Life. He came now as papal legate to reform the abuses which had arisen in the churches of Germany during the great schism; and when he came to his loved Deventer he hastened to indicate his especial regard for his old friends. He granted a special indulgence to both the brotherhood and the order, and permitted the Windesheim congregation to establish a second congregation, with equal privileges, to accommodate the rapidly increasing number of convents of Canons Regular.

Thomas survived his brother by nearly forty years. His cloister life moved on through three decades with the external monotony of an existence subjected to rule. Five years of the forty were years of pestilence and popular distress, which he duly chronicles. But the only real interruption of his routine which still has a living interest was his acquaintance with young Johan Wessel, who came to pursue his studies in Zwolle, being drawn by the charm of the Imitation into the neighborhood of its author. This probably was about 1460, when he sought and made Thomas’s acquaintance, and often conversed with him upon the greatest of themes. But the earliest biography of Wessel belongs to the next century, and is by a Protestant pastor in Bremen; so the statements that Wessel found Thomas and his brother monks all too superstitious, and rebuked the Mariolatry of the author of the Imitation, are open to doubt. That Wessel, the forerunner of Luther, influenced Thomas in the writing of the Imitation is a palpable absurdity.

For a short time he was procurator or steward of the monastery, a task which must have been uncongenial to him, but which he would discharge with his best diligence, as his first biographer, Jodocus Badius Ascensius, says he did. Then he was sub-prior a second time in 1448.

The chronicle of Mount St. Agnes ends with January 17th, 1471; its author died July 26th of the same year. His health had been singularly good, but toward the close of his life he suffered from dropsy. His eyesight never failed him, and he retained all his faculties in full vigor to the last. As the end drew near, the sense of all he had been to his brethren as a friend and counsellor deepened in them at the prospect of losing him. All that their love could do and his ascetic principles would permit, they did to lighten the burdens and relieve the pains of his illness. He died in his ninety-second year, after having been sixty-three years in the order and fifty-eight in the priesthood.

He was buried within the cloisters of the monastery. There his bones continued to rest even after the dissolution of the monastery at the Reformation in 1573, and thence they were disinterred in 1672 and placed in a shrine. But no miracles were wrought at his grave or by his bones. Whatever the faults of the Brethren of the Common Life, it was not in the atmosphere of the modern devotion that men learned to crave after such evidence of sanctity in the servants of God. So the brotherhood and its affiliated order have made no contributions to the list of Roman Catholic saints. There is room in that long and motley list for Giovanni da Capistrano, the cruel and implacable inquisitor, whose path across Europe was marked with blood and fire. But none has been found for the gentle and loving Thomas à Kempis, who has wooed millions of souls to a closer communion with his Master, and whose own life preached humility, patience, gentleness, renunciation of the world, conformity to the will of God, and likeness to Christ, as distinctly as does his great book. Well, he is content. Ama nesciri—love to be unknown—was a precept often on his lips and illustrated in his life. Of small matter to him would have been the attempt to deny his authorship of the Imitation, and the controversy of two centuries’ duration it provoked. Of no greater moment the refusal of the name of saint to one whose only miracles were wrought upon the spirits of his brethren. But the Church catholic says of him, “Surely this was a holy man of God.”

While the copying of books was the general employment of the brotherhood and of the order, there was from the first a good deal of independent authorship among them, and always on the lines of the “modern devotion.” Groote himself labored chiefly by preaching and correspondence. But some of his letters are tracts in that form, and had a wide circulation as such. Florens was not much even of a letter-writer, but he wrote one devotional tract which has been discovered. It was in Gerard Zerbolt of Zutphen, his altera manus, that he found a fit organ for the expression of his ideas in writing. To us Protestants Zerbolt is memorable as the author of a treatise asserting the right and duty of unlearned men to have good books—the Bible and their prayer-books included—in their own tongue. But he was much better known by his writing certain widely circulated books of devotion—modern, of course. Hendrik Mande, the Seer, was a Windesheim monk whose mysticism took the bolder and more ecstatic flight of Rusbroek, and like Rusbroek he found his native tongue more suitable than Latin. Lastly, Gerlach Peterszoon, sometimes called “the second Thomas à Kempis,” although he died in 1411, before Thomas himself had become an author, wrote in both Latin and Dutch sundry works, one of which still is reprinted for edification even by Protestants. Through all this literature runs the same strain of thought and feeling, in spite of personal differences. They all insist on a deeper renunciation of the world than is satisfied by any external monastic compliances. They all hold forth the imitation of Christ’s humility and meekness as the essence of the Christian life. They all insist on devotion to the will of God and good-will to men as the two essential channels in which the Christian life must run.