Soliloquies are used throughout Shakespearean tragedies in order to allow characters to disclose their innermost thoughts and feelings. Iago, then 'defies convention is an ironic character as he is duplicitous even when alone. Iago's soliloquies serve the purpose of creating dramatic irony and developing his motives and plot. There are many similarities between the two soliloquies present in Act 1, Scene 3 and Act 2, Scene 1 but there are also contrasts. Most noticeably Iagos transformation from typical Machiavellian villain, whom the audience feel complicity towards, to a more severe, deceitful murderer.
This transformation is evident in the difference of structure and diction in the soliloquies. Iago's first soliloquy is divisible in to three sections, each outlining a different motive. Line 381 up to the caesura in line 385 hints at the wealth motive by using diction associated with money 'expend', 'profit'. Roderigo is also repeatedly encouraged by Iago to 'put money enough in your purse' and shows his convincing character by making Roderigo believe that his only chance with Desdemona lies in Iago's hands.
There is an obvious change to a more vicious tone at the beginning of the second motive. This is symbolised by the short sentence of plosives 'I Hate The Moor' Despite the malevolent tone in this line the audience does not single this out as the only motive, due to Iago's insincerity throughout the rest of the play. The tone changes once more at line 392, were a sarcastic tone is adopted. This tone is immediately discernible because of the sibilance in Cassio's name.
The first soliloquy is also largely written in Iambic pentameter, which accompanied by the divided structure allows the audience to see Iago's controlled thoughts. This is a contrast to the second as at first...