Final answer:
The speaker in question is Macbeth, and during the fourth apparition, he sees a line of kings that are suggested to be the descendants of Banquo. This is significant as it contradicts Macbeth's ambitions and premonitions of his own lineage securing the throne, pushing forward the themes of fate, ambition, and guilt in Shakespeare's tragedy.
Step-by-step explanation:
Understanding the Fourth Apparition in Macbeth
The question pertains to a key moment in William Shakespeare's tragedy Macbeth, where the character Macbeth is confronted with several apparitions while visiting the witches for prophecies. Particularly, the fourth apparition that Macbeth sees is a vision of a line of kings, which are suggested to be descendants of Banquo, his comrade and fellow general. This revelation is alarming to Macbeth because it contradicts his ambitions and desires; instead of his lineage securing the throne, it appears to be Banquo's progeny who will rule. This is deeply troubling to Macbeth, as he has already committed regicide and several other atrocities in his quest for power, prompted by the witches' initial prophecies.
Throughout the play, Shakespeare uses apparitions and the supernatural as a narrative device to convey themes of fate, ambition, and guilt. These themes are closely examined through Macbeth's reactions to the apparitions, which foreshadow his eventual downfall. Notably, the prophecies provided by the witches play a critical role in driving Macbeth's actions, suggesting a predestined outcome and the inescapable nature of fate. Macbeth's encounter with the fourth apparition is a turning point, signifying the inevitable failure of his quest for absolute power and the consequences of his hubris.