There are two historians who were instrumental in identifying and defining the outlook/philosophy that we call 'Civic Humanism' amongst the writers, politicians and artists of renaissance Italy. Jacob Burkhardt, was one of the earliest writers to attempt to provide an explanation for the Renaissance, and the intellectual movement that he called 'Humanism' was key to his understanding of how the Renaissance actually happened.

Jacob Burkhardt, a German historian, born in the early 19th century, coined the term Humanism, describing it as a predominantly literary movement, one that began with the works of figures such as Petrarch, Dante and Giovanni Boccaccio, one based on working with and imitating the classics. This 'humanism' that Burkhardt identified would come to dominate all aspects of the Renaissance. Leading to the unique, and unprecedented flourishing of arts and culture in the 14th,15th and early 16th centuries.

Hans Baron, another German historian, writing a bit later, took Burkhardt's Humanism and renamed it 'Civic Humanism', or at least identified when what was primarily a literary movement became a school of political thought. Baron argues that political writers of the early quattrocento, along with prominent literary and artistic figures, practised an ‘almost dithyrambic worship of all things ancient’ rooted in the development of the classicist literary movement of the 14th century. This apolitical ‘classical humanism’ would be appropriated by the state of Florence and transmuted into a political ideology. Leonardo Bruni, (Chancellor of Florence, and an influential writer) would lead the field as the chief proponent of Florentine freedom, marrying the energetic worship of ancient times with the development of a political ideology of liberty and classical republicanism, in a new philosophy of civic humanism. This new civic humanism of the 15th century was so closely tied to the city and government of Florence that to all intents and purposes the two were indistinguishable. The catalyst of change was provided in the form of Florence's wars with the Sforza Dukes of Milan, a war in which Classical learning was of no use to the war effort: the quiet intellectual contemplation espoused by Aristotle was of no value to an embattled city, and instead humanism ‘would have to subordinate itself to the ideological and educational needs of the state’.

Civic Humanism espoused the classical values of liberty, democracy and republicanism, it encouraged the rich and great to sponsor great works as in the Roman tradition. Humanist texts where taught to the children of the elite, challenging the long held political orthodoxy which had been mainstream in medieval scholastic tradition: a rejection of the Augustinian view of the essentially negative value of politics, and its replacement with the classical tradition that viewed political involvement as ‘necessary to the dignity and perfection of humanity’. Political developments – not religious – became the important subject in ‘a turn from ‘otherworldliness’ to ‘reality’ as the principle of governance.

It is important to note that it was not atheism, religion was such an integral part of European society that the idea of rejecting it in anyway was anathema, but Civic Humanism was bound up in the larger intellectual developments, crucially, the discovery and subsequent promulgation of the Copernican model of the Solar system, which began to challenge the Augustinian concept of political power being derived from a celestial hierarchy, one that justified the divine right of Kings and Emperors to rule.

Sources: Jacob Burkhardt The Civilisation of the Renaissance in Italy (1867, 1878 English translation), Hans Baron The Crisis of the Early Italian Renaissance (1966)