盡管兩單詞經(jīng)常交替使用，但它們?nèi)匀痪哂幸欢ú町?。在日常英語(yǔ)中，ambiguity (含糊）多指因意思不明確而可作兩種選擇，因而嚴(yán)格地說(shuō)它更多是指“模棱兩可”；而vagueness (模糊）所指的選擇范疇則更為廣泛[1]。但在法律解釋領(lǐng)域，ambiguity有所擴(kuò)大，用于指因意思不明確而有多種（而不僅是兩種）選擇[2]。但這并不意味它便等同vagueness。事實(shí)上，兩者實(shí)質(zhì)性的區(qū)別在于法律文本中的ambiguity純粹是一種語(yǔ)病，屬于立法技術(shù)瑕疵，是法律起草人必須避免的現(xiàn)象；而vagueness 卻是法律語(yǔ)言的一大特征， 常是立法者在無(wú)法或不便作精確（precise)規(guī)定時(shí)，主動(dòng)或有意做模糊表達(dá)的結(jié)果，目的是給法官等留下一定自由裁量的空間，如in the reasonable time (在合理的期限之內(nèi)）便是一種vagueness而非ambiguity[3]。同樣，我國(guó)刑法中常出現(xiàn)的“數(shù)額特別巨大”或“情節(jié)特別嚴(yán)重”等表述也都是屬于“模糊”而非“含糊”詞語(yǔ)，都是立法者在不愿或無(wú)法進(jìn)行精確確認(rèn)時(shí)留給法官進(jìn)行自由裁量的典型范例，具體實(shí)踐中常由最高人民法院的司法解釋來(lái)確認(rèn)什么是“數(shù)額巨大”或“數(shù)額特別巨大”，以及什么是“情節(jié)嚴(yán)重”或“情節(jié)特別嚴(yán)重”等。

此外，ambiguity所導(dǎo)致的不確定性常起支配和主導(dǎo)作用，即起“不是/則是的作用”，因而尤其要小心避免。而vagueness的不確定性卻只與邊緣或輕微問(wèn)題相關(guān)[4]。
 
[1]“Ambiguities ( which involve an either/or choice) and vagueness (which involve a widely-ranging choice) as well as any mistakes should be carefully preserved. ” Cf. Cornelia E. Brown ( Hamilton College) , Riding the Waves of Fortune ： Translating Legislation of the Successor Soviet Republics, at p. 68, John Benjamins Publishing Company (1995).

[2]“In ordinary language this term is often confined to situation in which the same word is capable of meaning two different things，but, in relation to statutory interpretation, judicial usage sanctions the application of the word ambiguity to describe any kind of doubtful meaning of words, phrases or longer statutory provisions. ” Cf. Bryan A. Gamer, Black's Law Dictionary, at p. 79，7th edition, West Group (1999).

[3] Cf. Thomas R. Haggard, Legal Drafting, at p. 250, West Group (1996).

[4]“Ambiguity is a disease of language，whereas vagueness，which is sometimes a disease，is often a positive benefit. . . whereas ambiguity in its classical sense refers to equivocation, vagueness refere to the degree to which, independently of equivocation, language is uncertain in its respective applications to a number of particulars. Whereas the uncertainty of ambiguity in central, with an either-or challenge, the uncertainty of vagueness lies in marginal questions of degree. B Cf. Reed Dickerson，The Interpretation of Statutes，at pp. 48 ~49, West Group (1995).