ThisexpositionofGaloistheorywasoriginallygoingtobeChapterIofthecontinuationofmybookFerrnatsLastTheorem，butitsoonoutgrewanyreasonableboundsforanintroductorychapter，andIdecidedtomakeitaseparatebook.However，thisdecisionwaspromptedbymorethanjustthelength.FollowingthepreceptsofmysermonReadtheMasters！[E2]，ImadethereadingofGaloisoriginalmemoiramajorpartofmystudyofGaloistheory，andIsawthatthemoderntreatmentsofGaloistheorylackedmuchofthesimplicityandclarityoftheoriginal.ThereforeIwantedtowriteaboutthetheoryinawaythatwouldnotonlyexplainit，butexplainitintermscloseenoughtoGaloisowntomakehismemoiraccessibletothereader，inthesamewaythatItriedtomakeRiemannsmemoironthezetafunctionandKummerspapersonFermatsLastTheoremaccessibleinmyearlierbooks，[Eliand[E3].ClearlyIcouldnotdothiswithintheconfinesofoneexpositorychapter