Artemon
Πρόσεχε τῷ ὑποκειμένῳ ἢ τῇ ἐνεργείᾳ ἢ τῷ δόγματι ἢ τῷ σημαινομένῳ. → Look to the essence of a thing, whether it be a point of doctrine, of practice, or of interpretation.
Wikipedia EN
Artemon (Ancient Greek: Ἀρτέμων) (fl. c. 230 AD), a prominent Christian teacher in Rome, who held Adoptionist, or Nontrinitarian views. Little is known about his life.
He is mentioned as the leader of a nontrinitarian sect at Rome in the third century. He is spoken of by Eusebius of Caesarea as the forerunner of Paul of Samosata, an opinion confirmed by the acts of a Council of Antioch in 264, which connect the two names as united in mutual communion and support. Eusebius and Theodoret describe his teaching as a denial of Christ's divinity and an assertion that he was a mere man, the falsification of Scripture, and an appeal to tradition in support of his errors. Both authors mention refutations: Eusebius an untitled work, Theodoret one known as The Little Labyrinth, which has been attributed to a Roman priest named Caius, and more recently to Hippolytus of Rome, the supposed author of the Philosophoumena.