DECREE. - It is the particular form that the written orders and measures of the constituted power assume on given occasions. Decrees are as a rule emanations of the administrative function, although they are also found among the acts of the judicial and legislative power. In Roman law the decree was now an administrative act, now a judicial act, although it is not always easy to distinguish when it has the one or the other character.
In the law of the Church this name was given not only to acts of government, but also to the measures of the judge apart from the sentence, and to various enactments of the legislative power. In ancient times the acts of the supreme pontiff were called decreta as opposed to the acts of the Councils called statuta (Dict. Grat. ad c. 2 D. 3); for this reason the pontifical constitutions containing decisions and general and particular norms were anciently called decretals. The disciplinary decisions of certain councils, among them that of Trent, also bore this name. The name of decree was likewise given by antonomasia to various collections of sources, principally those of Burchard, of Ivo and of Gratian (v. COLLEZIONI CANONICHE).
In current canon law too, decrees are acts proper, for the most part, to the executive power. Such are, for example, the decisions and resolutions of the Holy Congregations (can. 1389), as well as the orders and measures of bishops and other prelates, given by way of administration (cann. 345, 513 § 2, 1601, 2152 § 2, 2187).
In the procedural field, this term designates the various measures of the judge that do not have the name and value of sentences (cann. 1868, 1840); in the legislative field, the disciplinary laws and the doctrinal decisions of the Councils retain this name (cann. 227, 291).
Of particular importance are the decrees of the Roman Congregations, which are distinguished into general and particular, according as the decisions given or the norms established concern particular persons and cases, or are directed to the generality.
Particular disciplinary decrees are equivalent to precepts, and bind only their addressees, while remaining for others an authoritative directive norm for the interpretation of the law in similar cases. General decrees, on the other hand, provided they are approved by the pontiff and legitimately promulgated, constitute a general juridical norm.
The same is to be said of doctrinal decrees, whether general or particular, to which, although they are not articles of faith, it is not lawful to deny assent, since they are acts of the ordinary magisterium.
Bibliography2 works
Zaccaria da San Mauro