Therefore, pleasure (and happiness) is not simply produced by the absence of pain but out of a particular desire that demands no pain at all.
Mike I can see why you would say "no pain" because of the point that the two feelings are separate and distinct. But in terms of 'demanding no pain at all' you would also keep in mind that we sometimes choose pain in order to produce pleasure, so while they are not the same feeling, a pleasure that is purchased at the cost of a particular pain might be a pleasure that we would choose, despite the cost in pain, would it not?