One of the most important contributions of modern jurisprudence is the theory of principle, which affirms another legal norm besides rule. However, because principle is necessary connection with discretion, reasoning by principle will be very arbitrary; especially when principles contradict with rules. So, we must find how to restrict that character of principle in order to keep the determinacy of legal reaconing. But,the present two restrict conditions, the end of rules and the judgment of individual case, have some defaults. In this article, we think only the three new conditions are efficient,the general condition, principle of proportionality and fit the legal system. |