‘And what’s he then that says I play the villain?’ is one of a number of major soliloquies spoken by Iago, the villain and chief architect of William Shakespeare’s Othello. We’ve previously analysed Othello here, but now let’s take a closer look at the speech which begins ‘And what’s he then that says I play the villain?’, which is found near the end of Act 2 Scene 3.
As is our habit here at IL, perhaps the best way to offer an analysis of Iago’s soliloquy is to go through it section by section, summarising its meaning as we go.
A quick plot recap: in Cyprus on a military campaign, Iago got Cassio drunk and arranged a brawl, which he made sure Othello witnesses; Othello had to strip the recently promoted Cassio of his commission. Iago’s next plot is to convince Othello that Cassio is having an affair with Desdemona, Othello’s wife. He tells Cassio to ask Desdemona to put in a good word for him with Othello so he might get his commission back (but with the result that Othello will question why his wife would want to plead for Cassio).
And what’s he then that says I play the villain?
When this advice is free I give and honest,
Probal to thinking and indeed the course
To win the Moor again? For ’tis most easy
The inclining Desdemona to subdue
In any honest suit: she’s framed as fruitful
At the point in the play where Iago makes his ‘And what’s he then that says I play the villain?’ speech, Cassio has just left. Iago muses, on his own: who would call him, Iago, a villain for advising Cassio to do what he has suggested (ask 
Desdemona to put in a good word for him with Othello)? After all, it’s the best way for Cassio to win back his favour with Othello. What’s more, it’s easy to win Desdemona round to such an honest request. (Probal means the same as probable here.)
Note how the word ‘honest’ has already appeared twice in Iago’s soliloquy. As William Empson showed in his analysis of the word ‘honest’ in Othello (in his The Structure of Complex Words (Hogarth critics)), the word ‘honest’ was undergoing a curious journey when Shakespeare wrote the play in the early seventeenth century, as it came to be associated with selfish libertinism and independence, and even rogue behaviour. The word ‘honest’, then, is often deployed ironically in Othello, and we should be on our guard when the king of rogues, Iago, uses it repeatedly here.
As the free elements. And then for her
To win the Moor – were’t to renounce his baptism,
All seals and symbols of redeemed sin,
His soul is so enfetter’d to her love,
That she may make, unmake, do what she list,
Desdemona, Iago reflects, is as ‘fruitful’ (i.e., generous or benevolent) as the ‘free elements’ (traditionally: earth, air, fire, and water, all ‘free’ for man to use as he see fits).
And once Cassio has convinced Desdemona to put in a good word for him and win Othello round – well, he loves her so much, that he would renounce his Christianity (and thus endanger his immortal soul because his sins would no longer be redeemed) in order to keep her happy. He is so enthralled to her, by his love for her, that she can persuade him to do anything (or dissuade him from doing anything) that she chooses.
Even as her appetite shall play the god
With his weak function. How am I then a villain
To counsel Cassio to this parallel course,
Directly to his good? Divinity of hell!
It’s not clear what Iago means by ‘her appetite’ here. In the excellent Arden edition of the play, Othello: Revised Edition (The Arden Shakespeare Third Series), E. A. J. Honigmann glosses this as potentially meaning Desdemona’s inclination or fancy; alternatively, however, critics have interpreted ‘her appetite’ as meaning, in condensed form, Othello’s appetite or desire for her. Either is tenable, though perhaps it makes more sense her to choose the more syntactically likely reading and gloss Iago’s lines here as ‘even as her desire to do something will lord it over Othello’s natural instincts, which are weakened because he is enslaved by love’.
How, then, Iago asks himself – and us, his uneasy confidants in this scene – is he a villain, when he is giving good advice to Cassio? The ‘parallel course’ acknowledges that, of course, Iago intends to bring about Cassio’s destruction through advising him thus; but it’s true that even if he did have Cassio’s best interests at heart, he would advise him to do exactly the same. ‘Divinity of hell!’ appears to be an exclamation of frustration (compare Iago’s ‘O god of hell!’ earlier in the play), but cleverly, like that earlier outburst, fuses God and the Devil, which is fitting given Iago’s plan to appear benevolent and kind even as he plots Cassio’s further downfall.
When devils will the blackest sins put on
They do suggest at first with heavenly shows,
As I do now: for whiles this honest fool
Plies Desdemona to repair his fortunes
And she for him pleads strongly to the Moor,
I’ll pour this pestilence into his ear,
That she repeals him for her body’s lust;
When devils commit their darkest and most awful sins, they first put on a show of heavenly and good, much as Iago is doing now. And while Cassio, this honest fool (note that word again!), entreats Desdemona to help him recover his reputation and career, and while she pleads his case for him with her husband, Iago decides he will poison Othello against his own wife with wicked rumours to sully her good name, suggesting to Othello that his wife is only helping Cassio’s because she lusts after him.
And by how much she strives to do him good,
She shall undo her credit with the Moor.
So will I turn her virtue into pitch,
And out of her own goodness make the net
That shall enmesh them all.
This way, Iago reasons, the more she tries to help Cassio, the more she’ll undermine Othello’s trust in her fidelity. So, by doing this, Iago will turn her good intentions into black and foul ones (‘pitch’ is a black resin that used to be applied to wood to preserve and protect it), and he will use Desdemona’s own virtue to ensnare all of them: Cassio, Desdemona, Othello.