 One further problem of the agent-patient theory, Miller adds, is that if the act of conservation can bring about the existence of a thing over an interval, then there seems to be no reason that any sustaining act is needed after the moment of its creation. The interval of existence caused at its first moment could be long enough to include the object’s entire span of existence. So conservation over time appears to be unnecessary. Vander Laan (2022) explores whether Miller’s objection to the agent-patient theory can be circumvented by theories on which God’s conserving action brings about the later existence of the patient only in conjunction with additional, continuous divine activity.