This means that the commands of natural law do not depend on God's will, and thus form the first three commandments of the Ten Commandments. The last seven of the Ten Commandments do not belong to the natural law in the strictest sense. Whilst humanity's duties to God are self-evident, true by definition, and unchangeable even by God, mankind's duties to others (found on the second tablet) were arbitrarily willed by God and are within his power to revoke and replace (although, the third commandment, to honour the Sabbath and keep it holy, has a little of both, as humanity is absolutely obliged to render worship to God, but there is no obligation in natural law to do it on this day or that). Scotus does note, however that the last seven commandments: Scotus justifies this position with the example of a peaceful society, noting that the possession of private property is not necessary to have a peaceful society, but that "those of weak character" would be more easily made peaceful with private property than without. Hence, the last seven commandments do belong to the natural law, but not in the strictest sense, as they belong to the natural law by rectitude rather than by definition. Thomas Aquinas Whilst Thomas Aquinas, as a natural law theorist, is generally seen as holding that morality is not willed by God, Kelly James Clark and Anne Poortenga have presented a defence of divine command theory based on Aquinas' moral theory. Aquinas proposed a theory of natural law which asserted that something is moral if it works towards the purpose of human existence, and so human nature can determine what is moral. Clark and Poortenga argued that God created human nature and thus commanded a certain morality; hence he cannot arbitrarily change what is right or wrong for humans. Immanuel Kant The deontological ethics of Immanuel Kant has been cast as rejecting divine command theory by several figures, among whom is ethicist R. M. Hare. Kant's view that morality should be determined by the categorical imperative – duty to the moral law, rather than acting for a specific end – has been viewed as incompatible with divine command theory. Philosopher and theologian John E. Hare has noted that some philosophers see divine command theory as an example of Kant's heteronomous will – motives besides the moral law, which Kant regarded as non-moral. American philosopher