Have you considered how you can avoid and/or address impasses in a negotiation by probing deeper? Have you considered what tool you can use to make the process effortless? The answer is, yes you have, even if you have not considered it on a conscious level.
The way to uncover hidden desires of others, their goals, dreams, desires, especially when you think you don’t have an answer, is to pose the question, what if I knew the answer, what might it be? You can ask that question of yourself and pose it to the person to whom you’re speaking. In a negotiation, such questions can lead to a plethora of information and insight.
In your next and future negotiations, keep the question of, what if handy. Doing so and using it will lead to more fruitful negotiation outcomes.