It does not vary with time, but remains unchangeable . " He also was familiar with Isidore of Seville or Isidorus Hispalensis ( c . 570 636 ) who wrote of law : " In determining the nature of law, there must be three conditions : the fostering of religion, in as much as it is proportionate to the Divine law; that it is helpful to discipline, in as much as it is proportionate to the natural law; and that is further the common weal, in as much as it is proportionate to the utility of mankind . " Bracton used these works as a basis for his legal philosophy.
