The second handbook is attributed to one of the most influential rhetoricians of the second century, Hemogenes of Tarsus. But there is no preface to his work and the exercises are brief; therefore, many doubt its authenticity. But the third handbook is attributed to Aphthonius of Antioch, student of the great sophist Libanius during the second half of the fourth century. This is the most widely used and referenced handbook that became the standard on the practice of progymnasmata. His treatises were combined with rhetorical treatises of Hermogenes on stasis theory and style to create the “Hermogenic Corpus.”