Why did Leopold von Ranke criticize Francesco Guicciardini’s historical writing?

Leopold von Ranke criticized the historical writing of Francesco Guicciardini in his work Zur Kritik neuerer Geschichtsschreiber, using him as a primary example of faulty historiographical practice.1

Ranke’s critique focused on three specific failures in Guicciardini’s methodology:

• Fabrication: He demonstrated that Guicciardini invented the content of many speeches he reported in his narratives.1
• Lack of firsthand knowledge: He pointed out that Guicciardini wrote about many events for which he could not have possessed any personal knowledge.1
• Unoriginality: He noted that even when Guicciardini did have personal access to events, he frequently relied on and copied from the accounts of his contemporaries rather than conducting independent research.1

By highlighting these flaws, Ranke sought to establish a more rigorous standard for historical scholarship, emphasizing the necessity of using primary sources—such as letters, diaries, and reports from embassies—to show how events "actually occurred" (wie es eigentlich gewesen).1