Clement of Alexandria
Τὸ νικᾶν αὐτὸν αὑτὸν πασῶν νικῶν πρώτη τε καὶ ἀρίστη. Τὸ δὲ ἡττᾶσθαι αὐτὸν ὑφ' ἑαυτοῦ πάντων αἴσχιστόν τε ἅμα καὶ κάκιστον. → Τo conquer yourself is the first and best victory of all, while to be conquered by yourself is of all the most shameful as well as evil
Wikipedia EN
Titus Flavius Clemens, also known as Clement of Alexandria (Ancient Greek: Κλήμης ὁ Ἀλεξανδρεύς; c. 150 – c. 215 AD), was a Christian theologian and philosopher who taught at the Catechetical School of Alexandria. Among his pupils were Origen and Alexander of Jerusalem. A convert to Christianity, he was an educated man who was familiar with classical Greek philosophy and literature. As his three major works demonstrate, Clement was influenced by Hellenistic philosophy to a greater extent than any other Christian thinker of his time, and in particular, by Plato and the Stoics. His secret works, which exist only in fragments, suggest that he was familiar with pre-Christian Jewish esotericism and Gnosticism as well. In one of his works he argued that Greek philosophy had its origin among non-Greeks, claiming that both Plato and Pythagoras were taught by Egyptian scholars.