Κτησίας
κάλλιστον ἐφόδιον τῷ γήρᾳ ἡ παιδεία (Aristotle, quoted by Diogenes Laertius 5.21) → the finest provision for old age is education
Wikipedia EN
Ctesias (/ˈtiːʒəs/; Greek: Κτησίας; fl. fifth century BC), also known as Ctesias of Cnidus, was a Greek physician and historian from the town of Cnidus in Caria, then part of the Achaemenid Empire.
Ctesias, who lived in the fifth century BC, was physician to the Achaemenid king, Artaxerxes II, whom he accompanied in 401 BC on his expedition against his brother Cyrus the Younger. Ctesias was part of the entourage of King Artaxerxes at the Battle of Cunaxa (401 BC) against Cyrus the Younger and his Greek mercenaries called the Ten Thousand, when Ctesias provided medical assistance to the king by treating his flesh wound. He reportedly was involved in negotiations with the Greeks after the battle, and also helped their Spartan general Clearchus before his execution at the royal court at Babylon.
Ctesias was the author of treatises on rivers and on the Persian revenues as well as an account of India entitled Indica (Ἰνδικά), and of a history of Assyria and Persia in 23 books, entitled Persica (Περσικά) that was written in opposition to Herodotus in the Ionic dialect. Professedly, the work was founded on the Persian Royal Archives.
Russian (Dvoretsky)
Κτησίας: ου ὁ Ктесий (родом из Книда в Карии, врач Артаксеркса Менона, сопровождавший его в войне с Киром в 401 г. до н. э.: автор трудов «Περσικά» в 23 книгах, в котором излагалась история Персии с древнейших времен до 398 г. до н. э. - от них сохранились фрагменты и краткое изложение Фотия, и «Ἰνδικά» - сохранилось тж. краткое изложение Фотия) Xen., Arst.