Why did Vico believe people can know human institutions better than the physical world?

Giambattista Vico argued that humans can achieve a deeper, more certain knowledge of history and human institutions than of the physical world because of the principle that to truly know a thing, one must have created it.1

In Vico’s view, the natural world is the creation of God, and therefore only God possesses perfect knowledge of it. Conversely, the "world of nations"—the realm of human history, actions, and social institutions—is the product of human creation. Because humans are the authors of their own social and historical reality, they are uniquely positioned to understand it from within.1

This perspective led Vico to emphasize that historical inquiry requires a different methodology than the natural sciences. Rather than seeking to impose external, abstract laws upon the past, he believed historians must enter imaginatively into the spirit of different ages to understand the specific outlooks and attitudes that shaped them. By recognizing that human nature is historical and subject to change, Vico sought to establish history as a reputable discipline distinct from the study of the nonhuman world.1