▁need ▁for ▁happiness ▁will ▁be ▁ful filled , ▁because ▁happiness ▁is ▁the ▁experience ▁of ▁knowing ▁that ▁you ▁are ▁particip ating ▁in ▁the ▁ideal . ▁ ▁Sig mund ▁Fre ud ▁ ▁In ▁Fre ud ian ▁psych ology , ▁er os , ▁not ▁to ▁be ▁confused ▁with ▁lib ido , ▁is ▁not ▁exclus ively ▁the ▁sex ▁drive , ▁but ▁our ▁life ▁force , ▁the ▁will ▁to ▁live . ▁It ▁is ▁the ▁desire ▁to ▁create ▁life , ▁and ▁fav ors ▁product ivity ▁and ▁construction . ▁In ▁early ▁ps y cho anal yt ic ▁writ ings , ▁instinct s ▁from ▁the ▁er os ▁were ▁opposed ▁by ▁forces ▁from ▁the ▁e go . ▁But ▁in ▁later ▁ps y cho anal yt ic ▁theory , ▁er os ▁is ▁opposed ▁by ▁the ▁destruct ive ▁death ▁instinct ▁of ▁Th an atos ▁( de ath ▁instinct ▁or ▁death ▁drive ). ▁ ▁In ▁his ▁ 1 9 2 5 ▁paper ▁" The ▁Res ist ances ▁to ▁Ps y cho - Anal ysis ", ▁Fre ud ▁explains ▁that ▁the ▁ps y cho anal yt ic ▁concept ▁of ▁sexual ▁energy ▁is ▁more ▁in ▁line ▁with ▁the ▁Plat onic ▁view ▁of ▁er os , ▁as ▁expressed ▁in ▁the ▁Sym pos ium , ▁than ▁with ▁the ▁common ▁use ▁of ▁the ▁word ▁" sex " ▁as ▁related ▁primarily ▁to ▁gen ital ▁activity . ▁He ▁also ▁mentions ▁the ▁phil os opher ▁Sch open h auer ▁as ▁an ▁influence . ▁He ▁then ▁goes ▁on ▁to ▁confront ▁his ▁advers aries ▁for ▁ign oring ▁such ▁great ▁prec urs ors ▁and ▁for ▁t