Gustav Kirchhoff
From 1884, he studied physics and mathematics at the University of Graz, where he was influenced by the philosophical teachings of Alexius Meinong (1853–1920). Following his studies at Graz, he continued his education in Berlin, where his instructors included Hermann von Helmholtz and Gustav Kirchhoff. He received his habilitation at the University of Innsbruck, where in 1902 he became an associate professor.