ourse ", ▁and ▁hence ▁the ▁introduction ▁of ▁the ▁inform al ▁into ▁otherwise ▁imper ative ▁logic . ▁He ▁reviews ▁J ør g ensen ' s ▁par ado x ▁to ▁introduce ▁de ont ic ▁logic , ▁and ▁acknowled ges ▁this ▁innov ation ▁by ▁Georg ▁Hen rik ▁von ▁Wright . ▁ ▁See ▁also ▁ ▁Crit ical ▁legal ▁studies ▁ ▁F ormal ism ▁( Y ar vin ) ▁ ▁Jud icial ▁activ ism ▁ ▁Leg al ▁posit iv ism ▁ ▁Met ac ogn ition ▁ ▁Original ism ▁ ▁Re ason able ▁doubt ▁ ▁Rule ▁according ▁to ▁higher ▁law ▁ ▁Foot notes ▁and ▁references ▁ ▁External ▁links ▁ ▁Social ▁Theory ▁of ▁Law ▁ ▁Category : So ci ology ▁of ▁law ▁Category : Form al ism ▁( ph il osoph y ) ▁Category : The ories ▁of ▁law <0x0A> </s> ▁A ▁City ▁is ▁Not ▁a ▁Tree ▁is ▁a ▁widely ▁c ited ▁▁ 1 9 6 5 ▁ess ay ▁( l ater ▁published ▁as ▁a ▁book ) ▁by ▁the ▁architect ▁and ▁design ▁the or ist ▁Christopher ▁Alexander , ▁first ▁published ▁in ▁the ▁journal ▁Arch itect ural ▁Forum , ▁and ▁re - pub lished ▁many ▁times ▁since . ▁ ▁In ▁ 2 0 1 5 ▁the ▁ess ay ▁was ▁published ▁as ▁a ▁book ▁including ▁new ▁ex eg esis ▁comment aries ▁on ▁the ▁original ▁ess ay ▁from ▁other ▁architect s , ▁engine ers ▁and ▁phys ic ists . ▁ ▁A ▁City ▁is ▁Not ▁a ▁Tree ▁has ▁been ▁widely ▁described ▁as ▁a ▁land mark ▁text , ▁and ▁the ▁Resource ▁for ▁Urban ▁Design ▁Information