Final answer:
The question refers to Iago from Shakespeare's 'Othello,' who plots against Othello and Cassio. Excerpts from other Shakespeare plays like 'Macbeth' suggest a broader theme of ambition and deceit in literature.
Step-by-step explanation:
The question refers to two characters from William Shakespeare's plays. Iago is a character from Othello, who vows to destroy Othello and Cassio out of jealousy and spite.
Additionally, the mention of characters like Duncan and Macbeth suggests the student is studying Shakespeare's Macbeth, where Macbeth is led to ruin by his ambition and manipulation by external forces, including his wife, Lady Macbeth.
In the context of the question, 'Iago privately vows to destroy the following two men,' we are focusing on the play Othello, where Iago's deep-seated animosity drives the plot forward and leads to the eventual tragedy of the characters involved.
These excerpts from different plays highlight common themes of deceit, ambition, and the destructive nature of certain human emotions.