法不溯及既往的公法意義

《立法法》確立的“從舊兼有利”帶有明顯的內在矛盾:第一，新法已經施行，卻仍要適用已被廢止的舊法;第二，“從舊”與“有利”可能發生衝突。多年來，這種內在矛盾不斷積累和發展，使得“從舊兼有利”在公法中基本喪失了在新舊法交替之際提供有效的法律適用規則的功能。行政裁判實踐中存在大量以“新法已經代替舊法”為由的“從新”，就是明證。跳出“從舊兼有利”的窠臼，區分法律上的既成事實與物理上的既成事實、法不溯及既往與舊法存續，以新法的即時效力為原則，是法不溯及既往在公法中的應有之義。

The “observing old laws and the law favorable to the parties concerned” established in the Legislation Law of the People􀆳s Republic of China has obvious inner contradictions. First, even though the new law has been implemented, the repealed old law is still applicable. Second, “observing old laws” and “the law favorable to the parties concerned” may conflict with each other. These inner contradictions have been accumulating and developing for many years, making “observing old laws and the law favorable to the parties concerned” in public law basically lose the function of providing effective applicable rules at the time of alternation of the old and new laws. This is manifested in that a large amount of “applying the new law” by reason of the fact of “the new law has replaced the old law” in the administrative judicial practice. The non-retroactivity in public law requires to abandon the concept of “observing old laws and the law favorable to the parties concerned”, to distinguish between the fait accompli in law and in practice, and between non-retroactivity of the law and survival of the old law, and to take the immediate effect of the new law as the principle.