Theodorus of Gadara () was a Greek rhetorician of the 1st century BC from Gadara (present-day Um Qais, Jordan)Blank, David, "Philodemus", The Stanford Encyclopedia of Philosophy (Spring 2019 Edition), Edward N. Zalta (ed.), accessed 3 June 2020.Strabo's Geography 16.2.29 who founded a rhetorical school in his native city. According to the Suda, he taught future Roman emperor Tiberius the art of rhetoric. Suetonius (c. 69 – after 122 AD) wrote of Tiberius that:
Theodorus was one of the two most famous rhetoric teachers of his time, the other being Apollodorus of Pergamon. Students of Apollodorus were commonly referred to as Apollodoreans, while students of Theodorus were known as Theodoreans.Quintilian, Institutio Oratoria, 2.11.2, esp. 3.1.18
He participated in sophistic contests with Potamo of Mytilene and Antipater in Rome. The Suda claims that he had a son, Antonius, who became a senator under Emperor Hadrian.Suda Encyclopedia, th.151
Works According to the Suda, Theodorus wrote the following books, among others: On Questions in Pronunciation (Περὶ τῶν ἐν φωναῖς ζητουμένων, in 3 books) On History (Περὶ ἱστορίας, 1 book) On Thesis (Περὶ θέσεως, 1 book) On the Similarity of Dialects and its Demonstration (Περὶ διαλέκτων ὁμοιότητος καὶ ἀποδείξεως, 2 books) On the Constitution (Περὶ πολιτείας, 2 books) On Coele Syria (Περὶ Κοίλης Συρίας, 1 book) On the Capacity of the Orator (Περὶ ῥήτορος δυνάμεως, 1 book)
References
Further reading
Editio princeps: Apollodori Pergameni ac Theodori Gadarei testimonia et fragmenta (accedunt Apollodoreorum ac Theodoreorum testimonia et fragmenta), a cura di Rossella Granatelli, Roma 1991.