Are there motives for Iago's hatred toward just about everyone (even himself), or is he just pure evil?

Katrina, this is a great question. I remember grappling with this at university. I suppose you might consider issues of self-esteem. Perhaps his mother didn't love him or he could never get the girl. I don't think Shakespeare meant those things. Iago was just pretty damn evil. His function was to be the vortex of chaos (did I just write vortex?) . Iago's function and joy was to see people becoming undone. If it was not Casio or Othello, it would have been somebody else. At the end of the play Othello looks at Iago's feet and says that he expected to see cloven hooves of the devil, "but that is a fable" he says. I'm not so sure. Iago was pretty much in an "evil" league of his own.