Αὐτάρκης ἔσῃ, ἂν μάθῃς τί τὸ καλὸν κἀγαθόν ἐστι → You will be contented with your lot if you learn what the honourable and good is
Plutarch, De virtute et vitioFrench (Bailly abrégé)
1ᵉ pl. de οἶδα, v. *εἴδω.
Russian (Dvoretsky)
ἴσμεν: 1 л. pl. praes. к *εἴδω.