The servant's capacity, volition, and acquisition are not merely empty labels. They explain why obedience or disobedience can be meaningfully attributed to a human agent. Intention, awareness, and voluntary choice make an action a subject of moral praise or blame.
An involuntary tremor, an accidental slip, and a deliberate harmful act are not morally equivalent. The occurrence of an event and the servant's legal accountability can depend on intention, knowledge, and choice.
The text does not treat human power as independent creation, but neither can meaningful responsibility be explained by denying every relation of an act to the human agent.