 An analytic treatment begins with the question under examination—the item that is to be analytically demonstrated. A successful analysis separates out what is contained in the question until some previously known items are found. One example the authors provide is a sketch of an analysis of magnetic phenomena, summarizing a case that Descartes dealt with in some detail (IV.2, 236; Descartes Rules, rule 12 [CSM I, 49–50] and Descartes 1644, Part 4 [CSM I, 276–279]. Carefully attending to a lodestone, the goal is to