(Fedora from here: http://www.ikrush.com/fashion-atoz/Fedora, Movie screencap from here: https://cinephiliamedia.wordpress.com/2013/10/14/the-iago-effect/, poorly Photoshopped by yours truly)

“Lay thy finger thus, and let thy soul be instructed.” (2, 1, 242)

In this passage, Iago’s begun to set another part of his master plan into action. He needs Roderigo to be completely convinced of Desdemona’s alleged love for Cassio. In doing so, he lays out an interpretation of Desdemona’s nature, of a woman’s nature. Even though he’s actively trying to convince Roderigo of something as ridiculous as her supposed attraction to Cassio in this passage, it’s still clear that he truly believes what he says. He’s had to have thought about it long and hard in order to figure out what he’d say to get Roderigo to be thoroughly convinced. His view of Desdemona’s sexual nature then cannot be ignored and passed over, because Iago’s interpretation is undoubtedly a reflection of, and is informed by, a greater cultural opinion.

Essentially, Iago lays out Desdemona’s attraction to Othello as base desire, innate to a woman’s wretched nature. She was first attracted to Othello for his stories, but stories, in Iago’s opinion can only go so far in satisfying her, for “her eye must be fed” (2, 1, 246). Desdemona’s sexual appetite is so vain to be dependent on the appearance of her partner, and Othello, in Iago’s mind, is the “devil” (2, 1, 247). Iago believes that the longer she stays with Othello, the more her “delicate tenderness will find itself abused, begin to heave her gorge, disrelish and abhor the Moor” (2, 1, 253-255). Iago even says that her “nature will instruct her in it and compel her to some second choice” (2, 1, 255-256). He then proceeds to paint Cassio as the perfect subject of her attention — someone handsome and young. The most important part of his description of Cassio though, is his insistence on calling him a “knave”, which means villain. This is of course a reflection of Iago’s personal hatred of Cassio’s taking over the coveted military position, but it also serves to further reflect Iago’s hatred of Desdemona, who represents his view of all women. First, he says she was attracted to the devil, and now she is attracted to a villain. He believes that she is willing to shed her own good character and virtue for a good fuck from some nightmarish and evil figure, whether it be a Moor or a conniving military man.

Iago’s smart, so it may seem on a first read that this is him just trying to convince Roderigo, who is nowhere near as insightful as himself, of these “facts”. But in a series of actions that will be reflected in later posts, it becomes clear that Iago seriously doesn’t like women, and it just so happens that Roderigo is  impressionable enough to let Iago go and speak freely about it. Simple, stupid Roderigo, who’s lovestruck and is ripe ground for Iago’s musings. Roderigo, who is not privy to the master plan, and is simply a cog.