MORNING WAKE UP, CIRCUS VERSUS THEATER: "Love, sorrow, fear, triumph or revenge cannot be interpreted by purely acrobatic movements." -- Antony Hippisley Coxe, A Seat at the Circus

Further ...

 "After his first wild leap, the acrobat forgot the cause, and, impressed by its effect, became more interested  in evolving physical variations than in trying to express different feelings by similar movements."