Out of all the examples of Shakespeares animal imagery, it is perhaps that of “making the beast with two backs” that engenders the feelings of most disgust on a character, or indeed, an audience. The reference comes from Othello, where Iago tries to think of the very worst scenario he can possibly paint to a man considering his wifes fidelity, or otherwise. Iago refers also to a “black ram tupping” (mating with) earlier in the play, and to a “white ewe” when referring to the Othello’s own relationship to his wife. With these images in mind already, the human mind transposes the one image upon the other, rams, ewes, mating, beasts with two backs (mating couples) to paint what would be a loathsome and ugly scene for any newly-married man afraid for his wife’s loyalty.
Arguably, it is this very image which first fires Othello up with disgust, jealousy and rage and gives impetus to his murderous thoughts. He has only to think of Cassio in that situation with his wife, Desdemona,whom he formerly perceived to be pure as the driven snow, and he cannot see or think clearly due to blind rage. Iago has used the bestial propensities of animals to reduce a noble and loyal human being to their level, or worse, as at least animals cannot be blamed for not trying to overcome their animal instincts.
The number of backs mentioned is of significance. One back is a static image, almost sedate even. But two backs ? This suggests the vision of seeing two backs at the same time, and suggests therefore, that, to make matters worse, the couple are engaging in some sort of romp, rolling around, thus insinuating that Desdemona is a willing partner. This is a step too far for Othello as it implies culpability on her part. It is this perceived culpability that he later decides not to forgive which leads him to commit murder and damn himself.
