Sufficiency Principle: S’s doing A promotes p if it causes p to obtain.
For example, Behrends & DiPaolo (p.4) offer the following case, where Julie supposedly "promotes" her desire by pressing the button, even though it's no more likely to be fulfilled than if she did nothing (it is guaranteed either way):
Buttons 2. Julie has some desire. There is one button in front of her. She knows that if she pushes the button, her desire is guaranteed to be fulfilled. However, unbeknownst to Julie, if she does not push the button, Black will ensure that her desire is fulfilled.
Eden convincingly argues that we needn't accept the sufficiency principle. I'm inclined to think, stronger still, that we positively should not accept it. Here's why.