Lambda the Ultimate Object再訪

Object
状態を持ち
メッセージを渡して処理を依頼
  (define (make-person first-name last-name occupation age)
    (lambda (msg . args)
      (case msg
        ((get-full-name) (string-append first-name " " last-name))
        ((get-occupation) occupation)
        ...

 Object間の通信がメッセージだけだったら?