Explaining and criticizing the theory of "symmetrical Approach" in determining the extent of blame attached to plaintiff and defendant in fault-based civil liability

After adopting the theory of Contributory negligence and dismissing the All-or-No thing Rule, the issue of how to determine the extent of loss and Victim Fault was raised in fault-based civil liability. The key question is whether there is a difference between the defendant’s fault and the plaintiff’s. If the same act has been done by both sides and the other essential elements are the same, should the responsibility be equally shared by the two perpetrators, regardless of whether they are plaintiff or defendant? The European principles of civil responsibility and the prevailing theory of common law have adopted a "symmetrical approach to victim and defendant's behavior in determining each one's fault" and, equally, have considered the standard of reasonable care in evaluating their behavior. This view has been tempered in various ways and certain exceptions have been made to it in the Common law. Similarly, from the point of view of economic analysis and moral criticism there are some objections to this theory. This view, despite its popularity, seems to have left much criticism unanswered. In depicting an apt theory to address this issue, it will count a step forward to explain and criticize the mainstream theory.