It was at one time widely held, on the authority of Aristotle's Poetics^† that tragedy originated in a form of choral song called dithyramb, through dialogue between the chorus and its leader—who thereby became the first actor, representing a single individual. The Poetics also claims that the playwright Aeschylus was the first to introduce a second actor and to shift the dramatic emphasis from dialogue between an actor and the chorus to dialogue between two actors.

In Aeschylus' Suppliants the chorus has the "leading role" and almost all the dialogue takes place between single actors and the chorus rather than between two actors. This fit so neatly with the historical scheme described in the Poetics that the scholarly consensus held that the Suppliants was one of Aeschylus' earliest plays, written probably in the 470s BC, before he had fully developed his innovation.

That is what your sentence describes: the play reflects an early stage in the evolution of tragedy out of dithyramb.

In 1952, however, Oxyrhynchus Papyrus 2256 was published, which seemed to imply^‡ that the play was written much later, perhaps in 463 BC. This is what the remainder of your reading discusses.

^† I have to express this very hedgingly, because everything about the origins of Greek drams is controversial; the Poetics, for instance, is not a 'finished' work but very elliptical (it has been suggested that it is in fact a set of lecture notes), and there are today very grave doubts about whether Aristotle was in a position to know much about this aspect of his subject.

^‡Again, we're dealing with ambiguous evidence. The Oxyrhynchus Papyri are a huge mass of papyrus fragments, many (such as 2256) so small that their sense has to be teased out by inference.

It was at one time widely held, on the authority of Aristotle's Poetics^† that tragedy originated in a form of choral song called dithyramb, through dialogue between the chorus and its leader—who thereby became the first actor, representing a single individual. The Poetics also claims that the playwright Aeschylus was the first to introduce a second actor and to shift the dramatic emphasis from dialogue between an actor and the chorus to dialogue between two actors.

In Aeschylus' Suppliants the chorus has the "leading role" and almost all the dialogue takes place between single actors and the chorus rather than between two actors. This fit so neatly with the historical scheme described in the Poetics that the scholarly consensus held that the Suppliants was one of Aeschylus' earliest plays, written probably in the 470s BC, before he had fully developed his innovation.

That is what your sentence describes: tragedy evolved out of choral lyric, and the play reflects an early stage in that evolution.

In 1952, however, Oxyrhynchus Papyrus 2256 was published, which seemed to imply^‡ that the play was written much later, perhaps in 463 BC. This is what the remainder of your reading discusses.

^† I have to express this very hedgingly, because everything about the origins of Greek drams is controversial; the Poetics, for instance, is not a 'finished' work but very elliptical (it has been suggested that it is in fact a set of lecture notes), and there are today very grave doubts about whether Aristotle was in a position to know much about this aspect of his subject.

^‡Again, we're dealing with ambiguous evidence. The Oxyrhynchus Papyri are a huge mass of papyrus fragments, many (such as 2256) so small that their sense has to be teased out by inference.