The Argonautica (also Argonautika) is a Greek epic poem written by Apollonius Rhodius in the 3rd century BCE. The only surviving Hellenistic epic, the Argonautica tells the myth of the voyage of Jason and the Argonauts to retrieve the Golden Fleece from the mythical land of Colchis. Another, much less-known Argonautica, using the same body of myth, was composed by Valerius Flaccus during the time of Vespasian. The Argonautica differs in some respects from traditional or Homeric Greek epic, though Apollonius used Homer as his principal model. The Argonautica is much shorter than Homer's epics, with four books totaling less than 6,000 lines, while the Iliad runs to more than 15,000. Apollonius may have been influenced here by Callimachus' advocacy of brevity, or by Aristotle's demand for "poems on a smaller scale than the old epics, and answering in length to the group of tragedies presented at a single sitting" (Poetics). Argonautica meets Aristotle's requirements; each of the Argonautica's four books are around the same length as a tragedy. Tragedies were traditionally performed in groups of four, three tragedies and a satyr play, whose total length was very nearly that of the Argonautica. Though critics have concentrated on Homeric echoes in Argonautica, direct borrowings from tragedy, such as Euripides' Medea, can be found. Apollonius' epic also differs from the more traditional epic in its weaker, more human protagonist Jason J.F. Carspecken noted his character traits, which are more characteristic of the genre of realism than epic, in that he was: "chosen leader because his superior declines the honour, subordinate to his comrades, except once, in every trial of strength, skill or courage, a great warrior only with the help of magical charms, jealous of honor but incapable of asserting it, passive in the face of crisis, timid and confused before trouble, tearful at insult, easily despondent, gracefully treacherous in his dealings with the love-sick Medea..." Argonautica is often placed in a literary tradition that leads to the Hellenistic novel. It is also unlike the archaic Epic tradition in its many discursions into local custom, aetiology, and other popular subjects of Hellenistic poetry. Apollonius also chooses the less shocking versions of some myths, having Medea, for example, merely watch the murder of Absyrtus instead of murdering him herself. The gods are relatively distant and inactive throughout much of the epic, following the Hellenistic trend to allegorize and rationalize religion. Heterosexual loves such as Jason's are more emphasized than homosexual loves such as that of Heracles and Hylas, another trend in Hellenistic literature, as heterosexual love gained prestige. Many critics name the love of Jason and Medea in this book as the best and most beautiful part of the Argonautica, inspiring some of Apollonius' finest writing: So Love the Destroyer Blazed in a coil around her heart, her mind's keen anguish Now flushed her soft cheeks, now drained them of all color.