▁of ▁general ity — h ence ▁not ▁all ▁norm s ▁are ▁rules . ▁Indeed , ▁as ▁the ▁meaning ▁of ▁an ▁act ▁of ▁will , ▁a ▁norm ▁is ▁not ▁intr ins ically ▁rational ; ▁depart ing ▁from ▁Kant ▁both ▁back ▁toward ▁David ▁H ume ▁as ▁well ▁as ▁in ▁the ▁direction ▁of ▁contemporary ▁philosoph ical ▁posit iv ism , ▁K elsen ▁den ies ▁the ▁existence ▁of ▁practical ▁reason . ▁ ▁Leg al ▁science , ▁as ▁K elsen ▁would ▁like ▁it ▁to ▁be , ▁has ▁to ▁describe ▁a ▁legal ▁norm ▁without ▁either ▁evalu ating ▁it ▁or ▁adopt ing ▁it ▁as ▁an ▁evaluation . ▁This ▁can ▁be ▁done ▁by ▁distingu ishing ▁rig or ously ▁between ▁the ▁social ▁statement ▁that ▁is ▁the ▁norm ▁itself ▁and ▁the ▁legal - s cient ific ▁rest at ement ▁of ▁it ▁that ▁is , ▁or ▁is ▁contained ▁in , ▁a ▁description ▁of ▁the ▁norm . ▁K elsen ▁terms ▁the ▁norm ▁itself ▁a ▁' legal ▁norm ▁( Re chts norm )' ▁and ▁its ▁descript ive ▁rest at ement ▁a ▁' legal ▁proposition ▁( Re cht ss atz ) '. ▁ ▁Leg al ▁orders ▁For ▁K elsen ▁as ▁for ▁other ▁central ▁European ▁contempor aries , ▁norm s ▁occur ▁not ▁sing ly ▁but ▁in ▁sets , ▁term ed ▁' orders '. ▁The ▁ordering ▁principle ▁of ▁an ▁order ▁of ▁moral ▁norm s — and ▁of ▁an ▁order ▁of ▁natural ▁law , ▁if ▁one ▁could ▁exist — w ould ▁be ▁logical , ▁as ▁dedu ction . ▁From ▁the ▁general ▁norm ▁' do ▁not ▁kill ▁other ▁human ▁be ings