Hans Baron's fame rests largely upon his characterization of what he called “civic humanism.” Central to this is what he saw as the emergence in early fifteenth-century Florence of a new emphasis on the participation of the citizen in the government and civic life of a city-republic, and on the necessity of such participation for the nurturing of individual virtue and the prosperity and liberty of the city. Although his idea stirred controversy from the start, the term itself has become part of the common historical vocabulary, in spite of the shortcomings of Baron's formulation. That formulation has come under attack from both medievalists and Renaissance historians who disagree about the evolution and content of the phenomenon, its connection with republicanism, its chronology, and its geographical origin and extent. In particular, there has been much debate over Baron's claim that civic humanism arose during the intense struggle between Milan and Florence, in which Florence was saved only when Giangaleazzo Visconti of Milan died suddenly of plague in September 1402.

A review article by James Hankins shows that the controversy continues.