▁however , ▁natural ▁law ▁might ▁be ▁useful ▁in ▁determ ining ▁the ▁content ▁of ▁the ▁common ▁law ▁and ▁in ▁dec iding ▁cases ▁of ▁equ ity , ▁but ▁was ▁not ▁itself ▁identical ▁with ▁the ▁laws ▁of ▁England . ▁Non eth eless , ▁the ▁imp lication ▁of ▁natural ▁law ▁in ▁the ▁common ▁law ▁tradition ▁has ▁meant ▁that ▁the ▁great ▁oppon ents ▁of ▁natural ▁law ▁and ▁advoc ates ▁of ▁legal ▁posit iv ism , ▁like ▁Jer emy ▁Bent ham , ▁have ▁also ▁been ▁sta unch ▁critics ▁of ▁the ▁common ▁law . ▁ ▁Natural ▁law ▁juris pr ud ence ▁is ▁currently ▁under going ▁a ▁period ▁of ▁reform ulation ▁( as ▁is ▁legal ▁posit iv ism ). ▁The ▁most ▁prominent ▁contemporary ▁natural ▁law ▁jur ist , ▁Australian ▁John ▁Finn is , ▁is ▁based ▁in ▁Oxford , ▁but ▁there ▁are ▁also ▁Americans ▁Germ ain ▁Gr ise z , ▁Robert ▁P . ▁George , ▁and ▁Canadian ▁Joseph ▁Bo yle ▁and ▁Brazil ian ▁Em íd io ▁Brasile iro . ▁All ▁have ▁tried ▁to ▁construct ▁a ▁new ▁version ▁of ▁natural ▁law . ▁The ▁ 1 9 th - century ▁an arch ist ▁and ▁legal ▁the or ist , ▁L ys ander ▁Spo on er , ▁was ▁also ▁a ▁figure ▁in ▁the ▁expression ▁of ▁modern ▁natural ▁law . ▁ ▁" New ▁Natural ▁Law " ▁as ▁it ▁is ▁sometimes ▁called , ▁origin ated ▁with ▁Gr ise z . ▁It ▁focus es ▁on ▁" basic ▁human ▁goods ", ▁such ▁as ▁human ▁life , ▁knowledge , ▁and ▁a est h etic ▁experience , ▁which ▁are ▁self -