Diplomacy
Non-violent dispute is best settled through diplomacy. So long as a target is not hostilediplomacy can be used to settle issues, negotiate terms, or even seek assistance from/with other people. Diplomacy is counter to diplomacy. This means that both parties involved use diplomacy checks. The person with the higher roll wins the argument/dispute. This cannot be used in place of a haggle. Disposition can have an effect on diplomacy, but not all the time. When using diplomacy for a personal favor, is when disposition will apply. It won't apply when arguing over future actions, or making arguments to an arbiter.
Synergy: Having 5 points or more in diplomacy grants you a +2 synergy bonus to both haggle and Discern Intent.