The Italian Renaissance saw the birth of humanism, a worldly paradigm that paradoxically was born from a return to the study of the classics. Writers such as Petrarch and Pico Della Mirandola emphasized the inherent nobility of man and encouraged intellectual pursuits beyond the religious questions emphasized by medieval thinkers. Other writers, like Machiavelli, emphasized a hard-nosed, common-sense approach to politics. Painters and sculptors like Botticelli, Leonardo da Vinci, Michelangelo, and Donatello emphasized the human form in their works, and often chose secular themes. In finance, bankers like the Medici and others developed complex mercantile arrangements that pointed the way to modern ideas of credit. Scientists such as da Vinci and Galileo began to think about the natural world in new ways. All of these changes have been characterized as fundamentally modern.