Which "speech" are you referring to?

Oedipus is the protagonist of Sophocles' tragedy Oedipus Rex created in the 5th century BC. Oedipus is the king of Thebes admired by his people for helping them in all their troubles. As we can see, the requirement of high (the highest, in this case) position is fulfilled. This is no surprise, as Aristotle considered Oedipus the best of tragic hero examples. The king's personal qualities are very high too. His moral standards never allow him to do anything indecent in his life. When he finds out that it is predetermined to him to become a murderer of his own father, he leaves his home without understanding that he has made a step toward his tragic destiny.

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Macduff enters, carrying Macbeth's severed head and shouting "Hail, King of Scotland!" The men echo this shout and the trumpets flourish as Malcolm accepts the kingship. Malcolm announces that he will rename the current thanes as earls. He will call back all the men whom Macbeth has exiled and will attempt to heal the scarred country. All exit towards Scone, where Malcolm will be crowned as King of Scotland.

In this moment Macbeth was enlightened about his vulnerability.

Macbeth e-text contains the full text of Macbeth by William Shakespeare.

A tragic hero as a separate kind of characters was created for the genre of tragedy. Many great writers contributed to this type of characters, and an entire theory was built. We know numerous examples of tragic heroes whose primary goal is to convey the acutest feeling of pity and sadness. Aristotle called this feeling catharsis and saw it as an indelible part of the tragic. Today, however, tragic hero has changed. But the foundations of creating these characters can be still found in Aristotle's work.

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Macduff enters alone and shouts a challenge to Macbeth, swearing to avenge the death of his wife and children. As he exist, he asks Fortune to help him find Macbeth.

Shakespeare's Macbeth - A Tragic Hero :: Macbeth essays

Macbeth enters, asserting that he should not “play the Roman fool” and commit suicide (2). Macduff finds him and challenges him. Macbeth replies that he has thus far avoided Macduff but that he is now ready to fight. As they fight, Macbeth tells him that he “bears a charmed life”: he will only fall to a man who is not born of woman (12). Macduff replies that the time has come for Macbeth to despair: "let the angel whom thou still hast served / Tell thee Macduff was from his mother's womb / Untimely ripped"—Macduff was born through the equivalent of a caesarian section (13-16). Hearing this, Macbeth quails and says that he will not fight. Macduff replies by commanding him to yield and become the laughing stock of Scotland under Malcolm's rule. This enrages Macbeth, who swears he will never yield to swear allegiance to Malcolm. They fight on and thus exit.

Macbeth: Tragic Hero (An Essay). - FIELD OF THEMES

Malcolm tells his soldiers that they are near enough to the castle now to throw down the branches they carry. He announces that Siward and Young Siward will lead the first battle. He and Macduff will follow behind. The trumpeters sound a charge.

How is Macbeth a tragic hero? | eNotes

Malcolm, Siward, and the other thanes enter. Although they have won the battle, Malcolm notes that Macduff and Young Siward are missing. reports that Young Siward is dead and eulogizes him by stating that "he only lived but till he was a man, / The which no sooner had his prowess confirmed / In the unshrinking station where he fought, / But like a man he died" (6-9). After confirming that his son’s wounds were on his front—in other words, that the Young Siward died bravely in battle—Siward declares that he not wish for a better death for his son.