 What is meant here by an ultimate source, and not just a source? An agent is an ultimate source of her action only if, at the very least, something necessary for her action originates within the agent herself. It cannot be located in places and times prior to the agent’s freely willing her action. If an agent is not the ultimate source of her actions, then her actions do not originate in her, and if her actions are the outcomes of conditions guaranteeing them, how can she be said to control them? The conditions sufficient for their occurrence were already in place long before she even existed!