As a model of method, the Principia suggested itself. No other work in recent history had had such an impact on knowledge; no other book had revolutionized the understanding of nature as much as Newton’s masterpiece; and no other book contained so many discoveries in such rigorous form. Such rigor, it appeared, was the key to the extraordinary quality of its contents. Kant, who had studied Newton’s insights a decade earlier, now studied his guidelines, spelled out not only in the “Rules of Philosophy” of the Principia but also in the queries of the Opticks. In the final query (1979 [1730]: 404–5), Newton suggests the research strategy of an analysis of wholes into parts, followed by a synthesis of the identified causes into explanatory principles.