Sometenyearsago,whencompletingwithJ.-B.ZuberaprevioustextonQuantumFieldTheory,theseniorauthorwaspainfullyawarethatlittlementionwasmadethatmethodsinstatisticalphysicsandEuclideanfieldtheorywerecomingcloserandcloser,withcommontoolsbasedontheuseofpathintegralsandtherenormalizationgroupgivinginsightsonglobalstructures.Itwaspartlytofillthisgapthatthepresentbookwasundertaken.Alas,overthefiveyearsthatittooktocometolife,bothsubjectshaveundergoneanewevolution.Disorderedmedia,growthpatterns,complexdynamicalsystemsorspinglassesareamongthenewimportanttopicsinstatisticalmechanics,whilesuperstringtheoryhasturnedtothestudyofextendedsystems,Kaluza-Kleintheoriesinhigherdimensions,anticommutingcoordinates...inanattempttoformulateaunifiedmodelincludingallknowninteractions.Newandsophisticatedtechniqueshaveinvadedstatisticalphysics,rangingfromalgebraicmethodsinintegrablesystemstofractalsetsorrandomsurfaces.Powerfulcomputersorspecialdevicesprovide"experimental"meansforanewbrandoftheoreticalphysicists.Inquantumfieldtheory,applicationsofdifferentialtopology,geometry,Riemannianmanifolds,operatortheory...requireadeeperbackgroundinmathematicsandaknowledgeofsomeofitsmostrecentdevelopments.Asaresult,whensurveyingwhathasbeenincludedinthepresentvolumeinanattempttouncoverthebasicunityofthesesubjects,theauthorshavethesameunsatisfactoryfeelingofnotbeingabletobringthereaderreallyuptodate.Itispresumablythefateofsuchendeavourstoalwayscomeshortofaccomplishingtheirpurpose.