The doctrine of the perspicuity of Holy Scripture… means only that the truth, the knowledge of which is necessary to everyone for salvation, though not spelled out with equal clarity on every page of Scripture, is nevertheless presented throughout all of Scripture in such a simple and intelligible form that a person concerned about the salvation of his or her soul can easily, by personal reading and study, learn to know that truth from Scripture without the assistance and guidance of the church and the priest. The way of salvation, not as it concerns the matter itself but as it concerns the mode of transmission, has been clearly set down there for the reader desirous of salvation. While that reader mmay not understand the “how” of it, the “that” is clear.
~Herman Bavinck~
Reformed Dogmatics Vol. 1: Prolegomena (Grand Rapids, Michigan; Baker Academic; 2003) p. 477.
Ironically today, “perspicuity” means “transparently clear,” or the clarity of being so transparent.