-Themethodsusedmayvary,buttheprincipleisthesame.;changetenthousandtimeswithoutdepartingfromtheoriginalaimorstand;innoneofhischangehashedepartedfromhisstand;invariousguisestoservethesinglepurpose(of...);Nomatterhowmanychangesonehasmade,hehasnotdepartedfromhisline.;Thecentralthemeremainsthesame.