▁describes ▁the ▁bulk ▁of ▁the ▁variation ▁in ▁a ▁set ▁of ▁data , ▁is ▁more ▁likely ▁to ▁represent ▁something ▁object ively ▁real , ▁subsequent ▁factors ▁become ▁more ▁and ▁more ▁abstract . ▁Thus ▁one ▁would ▁expect ▁to ▁find ▁a ▁factor ▁that ▁roughly ▁corresponds ▁to ▁" left " ▁and ▁" right ", ▁as ▁this ▁is ▁the ▁dominant ▁fr aming ▁for ▁politics ▁in ▁our ▁society , ▁but ▁the ▁basis ▁of ▁E ys en ck ' s ▁" t ough / t ender - mind ed " ▁th esis ▁( the ▁second , ▁T - factor ) ▁may ▁well ▁represent ▁nothing ▁beyond ▁an ▁abstract ▁mathematical ▁construct . ▁Such ▁a ▁construct ▁would ▁be ▁expected ▁to ▁appear ▁in ▁factor ▁analysis ▁whether ▁or ▁not ▁it ▁correspond ed ▁to ▁something ▁real , ▁thus ▁rendering ▁E ys en ck ' s ▁th esis ▁unf als ifiable ▁through ▁factor ▁analysis . ▁ ▁Mil ton ▁Ro ke ach ▁ ▁D iss atisf ied ▁with ▁Hans ▁J . ▁E ys en ck ' s ▁work , ▁Mil ton ▁Ro ke ach ▁developed ▁his ▁own ▁two - axis ▁model ▁of ▁political ▁values ▁in ▁ 1 9 7 3 , ▁bas ing ▁this ▁on ▁the ▁ideas ▁of ▁freedom ▁and ▁equality , ▁which ▁he ▁described ▁in ▁his ▁book , ▁The ▁Nature ▁of ▁Human ▁Val ues . ▁ ▁Mil ton ▁Ro ke ach ▁claimed ▁that ▁the ▁defining ▁difference ▁between ▁the ▁left ▁and ▁right ▁was ▁that ▁the ▁left ▁str essed ▁the ▁importance ▁of ▁equality ▁more ▁than ▁the ▁right . ▁Despite ▁his ▁critic isms ▁of ▁E ys en ck ' s ▁t