Natural law in Aquinas shares the essential features of law in general: it belongs to mind and stands between end and activity. The mind here is the human mind, the end is happiness which is the natural end of persons as persons and the activity is virtuous activity. The latter is activity that accords with reason. Virtue is called for by the natural law. That is because a) virtue is the habit that inclines persons to rational activity, b) persons are naturally inclined to rational activity and e) to the natural law belong all those things to which persons are naturally inclined. And so the ideas of virtue, rational activity, happiness and natural end are all of them inextricably linked in the Thomistic natural law ethics.