Why did Giambattista Vico turn from Plato to Tacitus and Machiavelli?

Giambattista Vico initially encountered Plato as his first philosophical master, but a critical spirit led him to shift his focus toward the Roman historian Tacitus and the Italian political philosopher Niccolò Machiavelli.1

This transition occurred because Vico sought a more realistic understanding of human nature. While Plato’s philosophy often focused on ideals, Vico was drawn to Tacitus and Machiavelli because they portrayed human beings not as they "should be," but as they "unfortunately are". This shift toward observing humanity in its actual, often flawed state became a foundational element of Vico’s thought, contributing to his development of a philosophy that emphasized the historical reality of human actions, institutions, and the "world of nations" created by humans themselves.12