If I do not. Three great ones of the city,
In personal suit to make me his lieutenant,
Off-capped to him: and, by the faith of man,
I know my price, I am worth no worse a place.
But he, as loving his own pride and purposes,
Evades them, with a bombast circumstance
Horribly stuffed with epithets of war,
And, in conclusion,
Nonsuits my mediators. For, 'Certes,' says he,
'I have already chose my officer.'
And what was he?
Forsooth, a great arithmetician,
One Michael Cassio, a Florentine,
A fellow almost damned in a fair wife,
That never set a squadron in the field,
Nor the division of a battle knows
More than a spinster—unless the bookish theoric,
Wherein the togèd consuls can propose
As masterly as he. Mere prattle, without practice
Is all his soldiership. (1.1.9-28)
Iago claims that he hates Othello because Othello passed him over for a promotion and chose Michael Cassio as a lieutenant instead. Iago also says that Cassio doesn't know any more about warfare than a housewife or a spinster does – he's never been on the battlefield and his knowledge of war is more "bookish" than experiential. This passage speaks to the way warfare is considered a man's realm (women didn't participate in battle). It also raises the question of why Iago hates Othello so much – Othello's refusal to promote Iago is just one of several reasons Iago gives for setting out to destroy the general.