Aristotle's idea of deliberation is different from how we usually think about making decisions. He believed that we don't need to consider all possible choices before deciding. Even though our actions are up to us, they can still be uncertain and changeable. Our ability to reason plays a big role in this. Despite having the capacity to choose differently, once we make a decision, we can only act in one way. If it seems like we can change our minds, it's because new desires can influence our actions between deciding and acting.