法是公正合宜之術──一句羅馬法諺的釋讀

Ius est ars boni et aequi: A texual research on a Roman legal maxim

「Ius est ars boni et aequi」是凱爾蘇斯的名言。Ius是法，ars為術，boni et aequi乃公正合宜。法不僅是一種藝術，而且有著內在的體系，有著因人因地因時而異的特質。強調法是術，突出的是人的重要性，突出的是法的工具理性；公正合宜，不僅是法的內在的價值追求，也是法學家評判規則優良與否的標準。法是公正合宜之術，內含衡平之義，而衡平是羅馬法具有頑強生命力的重要機制。凱爾蘇斯的這一名言，理想與現實完滿結合，它表明了凱爾蘇斯等羅馬法學家頭頂星空，腳踏實地的特色。正是由於它的這一秉性，也讓這句法諺千古流傳。

Ius est ars boni et aequi is one of Clesus's maxim. As far as this dictum is concerned, Ius means law, ars art, and boni et aequi just and appropriate. The law is not only a kind of art, but also has its own internal system and a characteristic that differs in different people, different time and different places. It is to highlight the importance of men and the instrument rationality of the law by emphasizing that law is art; while the boni et aequi is not only the internal value pursuit of the law, but also is the norm with which the Roman jurists valuated whether the regulations were good or not. This maxim has a quality of equality in itself, and the equality is an important thing which gave the Roman law a strong life. This maxim is a combination of the ideal and the reality, and it indicated that Celsus and other Roman jurists’ quality of having the starry heavens in their minds and putting their feet on the ground. Because of this, this maxim has been handed down to now.