The battles with Leibnizianism in the 1740s were the great theater for Voltaire’s work in this regard. In 1740, responding to Du Châtelet’s efforts in her Institutions de physiques to reconnect metaphysics and physics through a synthesis of Leibniz with Newton, Voltaire made his opposition to such a project explicit in reviews and other essays he published. He did the same during the brief revival of the so-called “vis viva controversy” triggered by du Châtelet’s treatise, defending the empirical and mechanical conception of body and force against those who defended Leibniz’s more metaphysical conception of the same thing. In the same period, Voltaire also composed a short book entitled La Metaphysique de Newton, publishing it in 1740 as an implicit counterpoint to Châtelet’s Institutions. This tract did not so much articulate Newton’s metaphysics as celebrate the fact that he avoided practicing such speculations altogether. It also accused Leibniz of becoming deluded by his zeal to make metaphysics the foundation of physics. In the definitive 1745 edition of his Éléments de la philosophie de Newton, Voltaire also appended his tract on Newton’s metaphysics as the book’s introduction, thus framing his own understanding of the relationship between metaphysics and empirical science in direct opposition to Châtelet’s Leibnizian understanding of the same. He also added personal invective and satire to this same position in his indictment of Maupertuis in the 1750s, linking Maupertuis’s turn toward metaphysical approaches to physics in the 1740s with his increasingly deluded philosophical understanding and his authoritarian manner of dealing with his colleagues and critics.