“必须”与“应当”均为义务性法律规范的关键词。一般认为,这二者无大区别,可以混用。然而,在法律规范日益精确细密的时代,应该加以区分,以便立法者选择使用。 一、二者程度上不同 “必须”与“应当”都是表示一定的因果联系。必须表示一种确定不移的联系,在程度上,“必须”具有无条件性,即不论主体的意愿如何,客观上必然要求主体去实施某种行为、实现某种结果。必须句中的前件与后件之间相互对立,推论确凿不可动摇。因而常“必须”词的法律规范是无条件义务性法律规范。如刑法第67条2款:“被宣告缓刑的犯罪分子,如果被判处 “Must” and “should” are the key words of obligatory legal norms. Generally believed that there is no big difference between the two, you can mix. However, as the legal norms become more precise and precise, it should be distinguished so that legislators can choose to use it. First, the two have different degrees of “must” and “should” all represent a certain causal link. Must be expressed as an immutable link, to the extent that “must” be unconditional, that is, regardless of the wishes of the subject, objectively requires the subject to implement a certain behavior, to achieve some result. The antecedent and the consequent of the sentence must be opposite each other, and the corollary can not be shaken. Therefore, the legal norm of “must” is an unconditional and obligatory legal norm. For example, article 67, paragraph 2, of the Criminal Code: "A criminal sentenced to probation if sentenced