Nietzsche references Schopenhauer’s Samtliche Werke on page 21, but the German philosopher is more famous for his treatise The World as Will and Representation. In this essay, Schopenhauer envisions the world as the product of blind metaphysical agency.

A German statesman, Niebuhr became Germany’s foremost historian of ancient Rome. He inspired patriotism in his students at the University of Berlin through recourse to Roman governance. Nietzsche critiques Niebuhr’s concept of the superhistorical (an omniscient understanding of history) in Chapter 1 in order to establish his own (the eternal) in Chapter 10.

The British empiricist David Hume was an influential proponent of Enlightenment thought. He was also a historian, essayist, and economist. He is best known for his 1739 work A Treatise of Human Nature.