This book offers the English translation of 'Momento. Studi Galileiani', the most comprehensive and rigorously documented account of the process through which Galileo, having revealed the limitations of traditional theories of motion and weight, developed a new science of mechanics and dynamics. It traces how, in the midst of the Scientific Revolution, the tension between inherited doctrines and innovative inquiry led to a radical transformation in the conception of nature and its laws. By examining the evolution of scientific terminology and its conceptual implications, the book shows how Galileo’s mathematical approach reshaped the understanding of motion and natural processes, while confronting the intellectual resistance of his time. Combining detailed historical reconstruction with methodological insight, this study provides a crucial resource for scholars of early modern science, the history of physics and mathematics, epistemology, and the development of scientific language.