Theonomous ethics, an important theory of religious ethics, has invited numerous attacks from modern religious critics. The paper begins with a scrutiny of the main ideas of theonomous ethics and of the five opposing. The second part of the paper deals with the main arguments of these religious critics. First of all, the problems of theodicy will be addressed from three aspects, namely, the general moral intuition, the basic position of teleological ethics, and the basic principles of theories of definition and reference. The discussion is meant to illustrate that whereas the theory of theonomous ethics needs to be revised, the arguments given by the religious critics are not impeccable either. Some flaws in their arguments are listed and discussed in the paper. The following part is devoted to the assessment of the position of theonomous ethics in the traditions of Judaism, Islamism and Christianity. It is discovered that theonomous ethics not only does not belong to the main stream of the three religions, but also is criticized by dominating theologies. We can infer that taking theonomous ethics as the target of their attacking fires, the religious critics actually commit the mistake of "strawman argumentation." Basi cally the ethics of the three religions are rationalistic rather than theonomous in nature. The concluding part of the paper analyzes the autonomous characteristics of religious ethics with the focus on bilical ethics. The significance of the Ten Commandments, for example, can be fully understood in terms of rationality. As a conclusion the paper points out that autonomous rationality is the last criterion for biblical ethics.