Laudator Temporis Acti

Plutarch, A Letter of Condolence to Apollonius 28 = Moralia 116 c-d (tr. Frank Cole Babbitt):

There are two of the inscriptions at Delphi which are most indispensable to living. They are: "Know thyself" and "Avoid extremes," for on these two commandments hang all the rest.

δύ᾽ ἐστὶ τῶν Δελφικῶν γραμμάτων τὰ μάλιστ᾽ ἀναγκαιότατα πρὸς τὸν βίον, τὸ "γνῶθι σαυτὸν" καὶ τὸ "μηδὲν ἄγαν"· ἐκ τούτων γὰρ ἤρτηται καὶ τἄλλα πάντα.

Matthew 22.35-40 (KJV):

Then one of them, which was a lawyer, asked him a question, tempting him, and saying, Master, which is the great commandment in the law? Jesus said unto him, Thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy mind. This is the first and great commandment. And the second is like unto it, Thou shalt love thy neighbour as thyself. On these two commandments hang all the law and the prophets.

καὶ ἐπηρώτησεν εἷς ἐξ αὐτῶν [νομικὸς] πειράζων αὐτόν, Διδάσκαλε, ποία ἐντολὴ μεγάλη ἐν τῷ νόμῳ; ὁ δὲ ἔφη αὐτῷ "Ἀγαπήσεις Κύριον τὸν θεόν σου ἐν ὅλῃ καρδίᾳ σου καὶ ἐν ὅλῃ τῇ ψυχῇ σου καὶ ἐν ὅλῃ τῇ διανοίᾳ σου"· αὕτη ἐστὶν ἡ μεγάλη καὶ πρώτη ἐντολή. δευτέρα ὁμοία αὐτῇ, "Ἀγαπήσεις τὸν πλησίον σου ὡς σεαυτόν." ἐν ταύταις ταῖς δυσὶν ἐντολαῖς ὅλος ὁ νόμος κρέμαται καὶ οἱ προφῆται.