Corey Dyck considers the largely overlooked, but crucial influence of Tschirnhaus’s treatise on method, Medicina mentis, on the first ten years of Wolff’s career, during which he worked intensively on refining his (in)famous mathematical method. Dyck’s consideration of Wolff’s early writings—including the Philosophia practica universalis, mathematica methodo conscripta (1703)—reveals a persistent commitment to Tschirnhaus’s views on scientific methodology even as Wolff identified, and worked to rectify, its various shortcomings. More specifically, Dyck argues that part of Tschirnhaus’s importance for Wolff lies in his use of principles gained from experience as a foundation for the scientific enterprise he undertakes in the context of his broader philosophical rationalism. He shows, moreover, that this lesson from Tschirnhaus not only runs through Wolff’s earliest philosophical discussions but also continues to inform his major texts in logic and mathematics up to the publication of the German Metaphysics. The chapter thus shows Tschirnhaus to have exerted an influence on Wolff’s development that is comparable to that of Leibniz.