The above two statements could be supported to a certain extent from a study of the play by analysing Iago's character during soliloquies and his interaction with fellow characters, along with the outcome of his actions.
From the offset, we realise that Iago is indeed not a pleasant character- he has been able to establish the themes of evil, hatred, revenge, deceit and sexual vulgarity by the first scene. The play begins swiftly and we are caught up amongst the tense atmosphere and feelings- all created by Iago. Perhaps the reason Shakespeare began the play in the midst of such drama was to show that Iago is a controlling and leading character, a warning sign, with a considerably strong personality. Furthermore, Iago demonstrates his supreme intelligence and ability to alternate between different personalities as often as he cares to.
Iago's soliloquies give us the opportunity to see him in his most honest light- we are able to witness his ability to scheme and plan as the thought processes form and develop in his mind. Soliloquies are the one scenario that we can fully rely on Iago as an honest character- meaning that he is not restraining himself in any way, aswell as gaining access to the birth of plots which evolve elaborately. For instance, his first soliloquy not only confirms the extent to which his hate for Othello stretches and the ease he has in expressing it, we gather the feeling he is more than just a jealous husband; 'I would time expend such a snipe But for my sport and profit. This reference to Roderigo suggests that Iago is a bitter misanthropist- his dislike is not only channelled at Othello, it is at people in general. His hate is not driven by a reason, he is evil. This is followed by 'I hate the Moor And it is thought abroad that 'twixt my sheets He's done my office'. Primarily, it would seem that Iago is suffering from the act that Othello has supposedly committed with ...