Having entered the Society in 1588, he devoted his spare time from his duties to hagiographical studies. Having gathered from his research in the convent libraries of Flanders the conviction that ancient sources presented the saints in a light different from popular lives and collections, he conceived the plan of compiling a critical collection of biographies, based on the most authoritative sources. In 1607 he announced his program: *Fasti sanctorum, quorum vitae in Belgici bibliothecae manuscripta*, which was to embrace 18 volumes (3 of preliminary matter, 12 of lives of saints, 1 of martyrologies; 2 of indices and tables). The time taken by other occupations prevented him from carrying out the plan, which was later taken up by Fr. Bolland and his colleagues.
However, he published: *Martyrologium Romanum parvum* (Antwerp 1613), to which he added the Martyrology of Ado; *Vitae Patrum... historiam eremiticam complectentes* (ibid. 1615; also in PL 73 and 74); Thomas à Kempis, *De Imitatione Christi... cum vindicibus kempensibus* (ibid. 1617); *Chronicon Canonico-Regularium ordinis S. Augustini Capituli Windesemensis; accedit Chronicon Montis S. Agnetis* (ibid. 1621).