 In the life sciences, these issues were manifest in debates over the role of vital powers in the explanation of living properties, as these were developed particularly in French discussions in the complex interactions of Newtonian and Leibnizian-Wolffian natural philosophies. An influential example of this synthesis is Émilie Du Châtelet’s (1706–1749) Institutions de Physique (first ed. 1740, second ed. 1742). These hybrid Leibnizian-Newtonian syntheses, bringing together aspects of Newton’s “active” forces with the monad and substance theory of Leibnizianism, were subsequently extended into discussions of embryology by Pierre de Maupertuis (1698–1759), and as will be developed in the next section, by Georges-Louis LeClerc, Comte de Buffon (1707–88) in the 1740s.