The beginning section where Iago is the only subject furthering the plot that leads to Othello’s
downfall is from the beginning of the play until partway through Act 2, Scene 3. In the very beginning
Iago is clearly at least trying to do harm to Othello: he says that “In following him, I follow but myself”
(1. 1. 64) and that he wants to “Plague him with flies” (1. 1. 78) and that he wants to make Othello’s
“joy / ... / lose some color” (1. 1. 78-80). Iago first tries to break up Othello and his love, Desdemona,
by getting Roderigo to come with him to tell Brabantio that his daughter and Othello are “making the
beast with / two backs” which does not have any direct repercussions to the actual plot that ruins
Othello, but displays how clever and plotting Iago can be (1.1. 131). Iago displays this cleverness soon
again as Roderigo comes to him saying that he “will incontinently drown” himself (1. 3. 347), and soon
has Roderigo convinced to “sell all [his] land” (1. 3. 425). At this point, Othello is still in control of his
emotions: when Iago informs him that Brabantio is angry with him, Othello reasonably responds that
his “services ... / Shall out-tongue [Brabantio’s] complaints” and keeps calm (1. 2. 21-22). Iago gets
as far as forming his plan to “abuse Othello’s ear” (1.3. 438) with the lie that Cassio, who “hath a
person and a smooth dispose / To be suspected” (1. 3. 440-441), is “too familiar with [Othello’s] wife”
(1. 3. 439) and to even discredit Cassio by starting a fight between him and Roderigo before Othello’s
passion even has any effect.
The point in the play where Othello’s passion combines with Iago to further the plot to Othello’s
downfall begins in Act 2, Scene 3 when Othello enters and says “My blood begins my safer guides to
rule” till when Othello’s passion really takes over (2. 3. 219). A combination of Iago’s plotting and
Othello’s passion lead to Othello declaring that Cassio “nevermore be officer”: Iago caused Cassio to
get in that fight by instructing Roderigo to start a fight and by convincing Cassio to drink, and the fight
is what caused Othello to become overcome by anger and fire Cassio (265). Although starting a
drunken brawl like Cassio did is no doubt an offense that should be punished, an action should by no
means have cost Cassio his entire position. Iago soon uses Cassio’s desperation to get his “reputation
... / ... the immortal part” (2. 3. 281-282) of himself back and “Th’ inclining Desdemona” (2. 3. 360),
who is easy “to subdue / In any honest suit” (2. 3. 360-361), to make “the net / That shall enmesh them
all” (2. 3. 381-382) by getting Desdemona to plead to Othello for Cassio that he will “repair his
fortune” (2. 3. 374), and then telling Othello that “she repeals him for her body’s lust” (2. 3. 377).
