 Sanctions are not necessary to natural law if we consider it strictly as a system of divine rules. However, sanctions are necessary when morality functions as law. Sanctions are mechanisms for enforcement, where inherent motivating factors are either absent or underappreciated. Consider, as an example, the moral duty to care for one’s children. For most people, this carries inherent obligatory force arising from its being obviously good and necessary. Where a person fails to appreciate the inherent force of this duty, however, laws exist that require parents to provide the means of life and education for their children, and such laws stipulate compliance under threat of sanctions. To call the first instance a law seems unnecessary, but we can clearly see how the concept of a rule of law distinguishes the latter case. Sanctions provide motives when individuals fail to act on the responsibilities reason should on its own reveal and thereby compel. In the Essays on the Law of Nature, Locke writes,