Perhaps Iago is the only person not puzzled by Iago, and there are signs in the play that he isn't entirely clear about Iago either. We know his actions perfectly well, and he works as a dramatic figure, but we don't understand why he does what he does — we don't grasp his motivation. We observe his plot to destroy Othello by instilling jealousy (and incidentally Cassio and Desdemona) but we don't discover what motivates him to undertake such a plot — with its evil, its risk, and its extremity. Worse, we seem to apprehend that he has no motivation; he is a motivational blank tablet, ontologically not merely epistemologically. In The Apologetics of Evil Richard Raatzsch edges probingly around this void, trying his best to make sense of it: his book is astute, determined, sensitive — but not an unmitigated success. The puzzle of Iago persists.
Raatzsch is on the right track when he notes the phonetic affinity of “Iago” and “ego”: Iago is certainly egotistical, egoistic, and egocentric. He recognizes no standard beyond himself; indeed, he hardly seems to grasp the reality of other people at all, save as tools, marks and dupes — always means, never ends. Raatzsch sees the character Iago as an incarnation of what he calls the “the concept of Iago”, the idea he embodies: he is best understood as a paradigm or exemplar. But it is still unclear what concept he embodies. He seems like a pathological version of something, but of what exactly? Iago is memorable and exciting, and universally hated by audiences of Othello; we have strong feelings about him. He also seems locked in a kind of dark conceptual symbiosis with Othello — as if he is the other half of a hybrid organism. Othello is warm, ingenuous, honorable, trusting, yet fatally credulous and weak; Iago is none of those things, but cold, deceptive, manipulative, and impervious to anything but his own perverse will. We feel we understand Othello — only too well, in fact — while Iago challenges our normal ways of explaining human action. It all seems so gratuitous.
The introduction to the book can be found here.