Vico’s own view was that the mind does not make itself and for that reason cannot know how it has knowledge of itself. Concerning mathematical and even scientific certainty, Vico did not think we can arrive at it through clear and distinct ideas, as Descartes claimed. He claimed that mathematical knowledge is certainly true because the human mind has created the very standard for mathematical truth, or because we have made mathematics. However, God has made the physical universe, and only He can have certain knowledge about that. Vico did concede that when we do make things in nature, or through scientific experiment, we can gain knowledge from the confirmation of our hypotheses.

Unlike the Cartesians, who dismissed history as a hodgepodge of fiction and unconnected facts, Vico thought that the historian can achieve more certainty than the scientist because he is studying the story of a world made by humans.

He disagreed with Hugo Grotius (1583–1645), Thomas Hobbes (1588–1679), and others, who began with the idea of a state of nature or some other way of positing a static, unchanging human nature. He was wary of what we would call “anachronism,” or assuming that words had the same meanings in the past as they do now, or that people have always thought the same way. Vico believed that historical events change human ideas. Vico asserted that every theory “must start from the point where the matter of which it treats first began to take shape.” According to Vico, the way the historian can discover the minds and feelings of those in past times is to decode their language, myths, and customs. For example, he believed that what are considered metaphors, myths, and fables at one time may have been the literal truth to people in the past.