▁theory ▁of ▁law ▁( K elsen ' s ▁chapter ▁ 5 ). ▁ ▁II . ▁Law ▁and ▁Mor als ▁K elsen ' s ▁strict ▁separation ▁of ▁law ▁and ▁mor ality , ▁in ▁Chapter ▁Two ▁of ▁P ure ▁Theory ▁of ▁Law , ▁was ▁an ▁integral ▁part ▁of ▁his ▁presentation ▁of ▁the ▁P ure ▁Theory ▁of ▁Law . ▁The ▁application ▁of ▁the ▁law , ▁in ▁order ▁to ▁be ▁protected ▁from ▁moral ▁influence ▁or ▁political ▁influence , ▁needed ▁to ▁be ▁saf egu arded ▁by ▁its ▁separation ▁from ▁the ▁sphere ▁of ▁conventional ▁moral ▁influence ▁or ▁political ▁influence . ▁K elsen ▁did ▁not ▁den y ▁that ▁moral ▁discussion ▁was ▁still ▁possible ▁and ▁even ▁to ▁be ▁encourag ed ▁in ▁the ▁soci ological ▁domain ▁of ▁inter subject ive ▁activity . ▁However , ▁the ▁P ure ▁Theory ▁of ▁Law ▁was ▁not ▁to ▁be ▁subject ▁to ▁such ▁influ ences . ▁ ▁III . ▁Law ▁and ▁Science ▁In ▁Chapter ▁Three ▁of ▁P ure ▁Theory ▁of ▁Law , ▁law ▁is ▁defined ▁as ▁the ▁application ▁of ▁norm s ▁to ▁its ▁functions ▁within ▁the ▁del ine ations ▁of ▁a ▁science ▁of ▁law . ▁Science ▁was ▁generally ▁the ▁domain ▁of ▁the ▁caus al ▁understanding ▁of ▁ep ist em ological ▁data ▁and ▁its ▁primary ▁logical ▁and ▁caus ally ▁orient ed ▁technique ▁was ▁to ▁be ▁distinguished ▁from ▁the ▁norm ative ▁reasoning ▁as ▁was ▁to ▁be ▁found ▁in ▁the ▁P ure ▁Theory ▁of ▁Law . ▁Therefore , ▁the ▁legal ▁sciences ▁were ▁to ▁be ▁norm atively ▁based ▁in ▁distinction ▁from ▁the ▁physical ▁sciences ▁which ▁were ▁to ▁be ▁caus ally ▁based .