Oedipus Rex unconditional (Laius "will" have a son who will kill him). Both Aeschylus and Euripides write plays in which the oracle is conditional; Sophocles ... chooses to make Laius's oracle unconditional and thus removes culpability for his sins from Oedipus, for he could not have done other than what he did, no matter what action he took. This interpretation is supported by Jocasta's repetition of the oracle at lines 854–55: "Loxias declared that the king should be killed by/ his own son." In the Greek, Jocasta uses the verb "chrênai": "to be fated, necessary." This iteration of the oracle seems to
Tragedy time of the empire, the tragedies of two playwrights survive—one is an unknown author, while the other is the Stoic philosopher Seneca. Nine of Seneca's tragedies survive, all of which are "fabula crepidata" (tragedies adapted from Greek originals); his "Phaedra", for example, was based on Euripides' "Hippolytus". Historians do not know who wrote the only extant example of the "fabula praetexta" (tragedies based on Roman subjects), "Octavia", but in former times it was mistakenly attributed to Seneca due to his appearance as a character in the tragedy. Seneca's tragedies rework those of all three of the Athenian tragic playwrights whose