The audience is positioned to realise that Iago has a false outward appearance and cannot be trusted. This realisation serves as a foreshadowing of the events that lead to the downfall of Othello. The theme of deception gains depth and added meaning.
Iago's deception continues throughout the play. In Act II, Scene 1, Iago convinces Roderigo that Desdemona, now Othello's wife, is tired of Othello and is seeking a new partner, despite knowing that it is entirely untrue, so as to swindle him further. He convinces Roderigo that Desdemona is attracted to Othello's lieutenant, Cassio, and in order to gain Desdemona's favor, he first must disgrace Cassio. In this manner, Iago is able to deceive Roderigo into causing Cassio to lose his position as Othello's lieutenant, causing Iago to get promoted, which was Iago's true intent. As Iago says:.
" Knavery's plain face is never seen till used.".
This act further reinforces the audiences" belief that Iago is not to be trusted and emphasises the theme of deception ever present in the play.
The theme of deception is furthered again in Act III, Scene 3, whence Iago seeks to instil a distrust of Cassio in Othello. Iago arranges for Othello to walk in on a meeting of Desdemona and Cassio (the meeting actually being suggested by Iago as a means for Cassio to gain his position again). Cassio cannot face Othello yet from shame so departs as Othello enters. Iago then goes to sour the event in Othello's eye by insinuating that Cassio is less than decent. He does this as subtly as he can, creating suspicion by refusing to explain his comment:.
" Ha! I like not that.".
By refusing to explain himself, Iago causes Othello to suspect the worst, as Othello considers Iago to be an honest and thoughtful person. Because of this, Othello sees Iago's silence after such a comment to as Iago not wishing to alarm Othello or shame Cassio. This is further emphasised when Iago states:.