References to the phrase γνῶθι σεαυτὸν (know thyself) etched in stone on the Temple of Apollo at Delphi have for centuries abounded in Western literature, perhaps most significantly in the works of Plato. This phrase was also frequently cited by Protestants during and after the Reformation. A simple search of the various phrases γνῶθι σεαυτὸν, nosce teipsum, and cognosce teipsum in the Digital Library of Classic Protestant Texts turns up numerous results in works by authors from Martin Luther and Ulrich Zwingli to David Pareus and Peter van Mastricht. The phrase was also quite influential on John Calvin, who begins his Institutes with the argument that to know oneself and one’s God is the sum of all piety. Wolfgang Musculus also uses the phrase in his locus on creation in his Common Places. For Musculus the phrase “know thyself,” though uttered by a pagan oracle, is divinely inspired. Here I’ve transcribed a section of this locus from the English printing of 1563 (London: R. Woulfe):
For what agreeth more properly unto man, than next unto God his creator, to knowe himself? To this knowledge the same doth not invite us to be alone which Lactance saith in one place: “Great is the might of man, his reason is great, his misterie great, that not for naught Plato gave thanks to nature that he was borne a man, that after God there is nothing hygher than man, nothing created more excellent”: But it is also a great peece of our salvation, to know ourselves, wherein some gave also to understand, that the greatest parcel of wisdom is contained, which did continually put into mens heads the common proverb: γνῶθι σεαυτὸν, know thyself, as sent to us down from heaven. For who is it that knoweth not that it is principally required to the knowledge of man, not to be ignorant of the beginning and estate of mankinde? And the holy spirite seemeth in the holy scriptures to expresse the creation of man more carefully and diligently, than of any other creature, to this entent no doubt, that we should understand from the beginning of our nature that God in the making of man would set forth a singular peece of work, which should be farre passing al other creatures, & should come much nearer than any other to the glory of his godhead: and also because the knowledge of our own beginning, should much availe towards the consideration of the wisedom, goodness, and power of God, containing therein certain (as it were) principles of his heavenly Philosophie (Fol. 10).