Much of the discussion on robot and AI ethics seems to share images and representation of robots and autonomous machine, which derive from literatures including SCI FI novels. This article aims to reveal the implication and hidden ethical problems in the concept of robots in literatures by reviewing the etymological origin of terms concerning robots, namely, mechanism, android, and automaton. The usage of the last and its role in Greek myth shows that robots as character in dramas unavoidably have tragic role to make human-being misfortune. This can mean that robots in literatures, and the ethical discussion based on representation of robots appearing in literatures, have ethical problems in nature. Therefore, if we want to establish practical and realistic ethics of robotics, we need to intentionally ignore the representation of robots in literatures, and the rules of robots such as the three laws of robotics in Asimov's novels.