[1][2] After graduating, Hauser started his doctoral studies, earning a Ph.D. degree in scholastic philosophy and another in zoology from the University of Innsbruck.
[1] At this time he met Oscar Nedel, a Brazilian Jesuit Father who went to Europe in order to study natural sciences in Germany because he had been selected to be a professor in a new university.
[1] Hauser was ordained on June 21, 1955 in Brazil and in 1958 he helped to found the São Leopoldo School of Philosophy, Sciences and Literature that would later become Unisinos.
During this time he also became chaplain in the Brazilian Air Force in order to work with pastoral care and eventually became a pilot.
While working in Innsbruck, Hauser developed a new histological technique that eliminated the use of xylene, a toxical compound that facilitated paraffin infiltration in tissues to be sectioned, by replacing it with isopropyl alcohol, an almost unharmful substance.