This thesis examines the evolution of cosmology in the first half of the seventeenth century through a case study of the erudite Alessandro Tassoni and his Pensieri diversi, an encylopedia covering scientific, literary, historical, and philosophical topics. Highly successful during the seventeenth century, read even by Galileo Galilei, the Pensieri diversi has received little scholarly attention. However, it offers a significant contribution to our understanding of the evolution of early modern cosmology because it was published during the early seventeenth century (...) when profound changes in representations of the structure of the cosmos were occurring. Specifically, it sheds light on scientific debates in the decades immediately preceding Galileo’s Dialogo sopra i due massimi sistemi del mondo. With his Pensieri diversi, Tassoni facilitated the dissemination of scientific disputes across a wider public of erudite non-specialists by using an easy-to-read question and answer format. Yet, he did not simply reproduce opinions from late medieval thought and contemporaneous cosmological debates but instead offered his own critique. I analyse three key themes from the Pensieri diversi. These topics open up more nuanced understanding of those complex issues that, over time, led to epistemological changes in the field of the history of science. In order to point out Tassoni’s contribution to the science of early seventeenth century, I set his scientific and philosophical speculations in their historical and sociological context, and I also provide close textual and theoretical analysis of Tassoni’s cosmological ideas. Thus, I address, more generally, the relationship between scientific and scholarly culture at the dawn of the Scientific Revolution. (shrink)