Vico is best known for his verum factum principle, first formulated in 1710 as part of his De Italorum Sapientia. The principle states that truth is verified through creation or invention and not, as per Descartes, through observation:
“The criterion and rule of the true is to have made it. Accordingly, our clear and distinct idea of the mind cannot be a criterion of the mind itself, still less of other truths. For while the mind perceives itself, it does not make itself.”
This criterion for truth would later shape the history of civilization in Vico’s opus, the Scienza Nuova (The New Science, 1725), since civil life – like mathematics – is wholly constructed.