The present paper investigates the seventeenth-century debate on whether the agreement of all human beings upon certain notions—designated as the “common” ones—prove these notions to be innate. It does so by focusing on Descartes’ and Locke’s rejections of the philosophy of Herbert of Cherbury, one of the most important early modern proponents of this view. The paper opens by considering the strategy used in Herbert’s arguments, as well as the difficulties involved in them. It shows that Descartes’ 1638 and 1639 reading of Herbert’s On Truth—both the 1633 second Latin edition and Mersenne’s 1639 translation—was instrumental in shaping Descartes’ views on the issue. The arguments of Locke’s Essay opposing Herbert’s case for innatism are thus...