A copy of the Imitation exists today in Thomas’ handwriting, which concludes with these words: “Finished and completed by the hand of Brother Thomas à Kempis in the year of 1441 at the Monastery of Mount St. Agnes near Zwolle”. The book originally appeared about 20 years earlier, so Thomas is clearly referring to his having just finished copying, not writing, the book. It would not be unusual for him to copy his own book, for as a scribe he copied many books, but some have claimed that his not having signed his name as the author indicates that at best he gathered together the spiritual writings of Groote. However, it is extremely difficult to believe that the humble Thomas à Kempis would not credit the renowned Groote with the work, either in his own copy of the Imitation or his biography of Groote. Early copies of the Imitation do not name the author, but several contemporaries of Thomas à Kempis do credit him with the work.
Modern computer analysis of the vocabulary and sentence structure of Kempis’ work and Groote’s indicate that the language of the Imitation is like that of Thomas’ other books and unlike that of Groote’s writing. It is most probably only Thomas’ humility and lack of desire to claim any worldly honor for his book that allowed this question to arise.