Groote determined to change all that. The Brethren worked consistently in the scriptorium; afterwards, with the printing press, they were able to publish their spiritual writings widely. Among them are to be found the best works of 15th-century Flemish prose. The Brethren spared no pains to obtain good masters, if necessary from foreign countries, for their schools, which became centres of spiritual and intellectual life of the Catholic Church; amongst those whom they trained or who were associated with them were men like Thomas à Kempis, Dierick Maertens, Gabriel Biel, the physician Vesalius, Jan Standonck (1454–1504), priest and reformer, Master of the Collège de Montaigu in Paris, and the Dutch Pope Adrian VI.