Giorgio Baglivi (Latin: Georgius Baglivus; Croatian: Gjuro Baglivi; September 8, 1668 – June 15, 1707), born Giorgio Armeno and sometimes anglicized as George Baglivi, was a Croatian-Italian physician and scientist. He made important contributions to clinical education, based on his own medical practice. His advanced the "solidist" theory that the solid parts of organs are more crucial to their good functioning than their fluids, against the traditional belief in four humors. Baglivi, however, advocated against doctors relying on any general theory rather than careful observation. He was "a distinguished physiological researcher fascinated by the nerves, his microscopic studies enabled him to distinguish between smooth and striated muscles and distinct kinds of fibres."