Owing to his impoverished circumstances he was unable to begin his formal education until later in life. He was 16 when he entered the Latin school in Přerov (he later returned to this school as a teacher 1614–1618). He continued his studies in the Herborn Academy (1611–1613) and the University of Heidelberg (1613–1614). In 1612 he read the Rosicrucian manifesto "Fama Fraternitatis". Comenius was greatly influenced by the Irish Jesuit William Bathe as well as his teachers Johann Piscator, Heinrich Gutberleth, and particularly Heinrich Alsted. The Herborn school held the principle that every theory has to be functional in practical use, therefore it has to be didactic (i.e. morally instructive). In the course of his study he also became acquainted with the educational reforms of Ratichius and with the report of these reforms issued by the universities of Jena and Giessen.