▁types ▁of ▁explan atory ▁devices . ▁Schutz ' s ▁basic ▁argument ▁was ▁that ▁soci ology ▁cannot ▁ground ▁itself ▁and ▁that ▁ep ist em ology ▁was ▁not ▁a ▁lux ury ▁but ▁a ▁necessity ▁for ▁the ▁social ▁scient ist . ▁Par s ons ▁agreed ▁but ▁str essed ▁the ▁p rag m atic ▁need ▁to ▁dem arc ate ▁science ▁and ▁philosophy ▁and ▁ins isted ▁moreover ▁that ▁the ▁ground ing ▁of ▁a ▁concept ual ▁scheme ▁for ▁empir ical ▁theory ▁construction ▁cannot ▁aim ▁at ▁absolute ▁solutions ▁but ▁need ▁to ▁take ▁a ▁sensible ▁stock - t aking ▁of ▁the ▁ep ist em ological ▁balance ▁at ▁each ▁point ▁in ▁time . ▁However , ▁the ▁two ▁men ▁shared ▁many ▁basic ▁assumptions ▁about ▁the ▁nature ▁of ▁social ▁theory , ▁which ▁has ▁kept ▁the ▁debate ▁sim mer ing ▁ever ▁since . ▁The ▁article ▁was ▁stim ulated ▁by ▁a ▁series ▁of ▁inform al ▁discussion ▁group ▁meet ings , ▁which ▁Par s ons ▁and ▁several ▁other ▁colle agues ▁in ▁the ▁spring ▁of ▁ 1 9 5 1 ▁had ▁conducted ▁with ▁phil os opher ▁and ▁semi ot ician ▁Charles ▁W . ▁Morris . ▁His ▁interest ▁in ▁symbol ism ▁went ▁hand ▁in ▁hand ▁with ▁his ▁interest ▁in ▁Fre ud ' s ▁theory ▁and ▁" The ▁Super ego ▁and ▁the ▁Theory ▁of ▁Social ▁Systems ", ▁written ▁in ▁May ▁ 1 9 5 1 ▁for ▁a ▁meeting ▁of ▁the ▁American ▁Psych iat ric ▁Association . ▁The ▁paper ▁can ▁be ▁regarded ▁as ▁the ▁main ▁statement ▁of ▁his ▁own ▁interpretation ▁of ▁Fre ud , ▁but ▁also ▁as ▁a ▁statement ▁of ▁how