a contemplated marriage or to legitimize one already contracted; (b) in secret cases, or in public cases, or in both; (c) in foro interno only, or in foro externo (the latter includes also the former). Power of dispensing in foro interno is not always restricted to secret cases (casus occulti). These expressions are by no means identical. When a matrimonial impediment is common to both parties the bishop, in dispensing his own subject, dispenses also the other. By virtue of his power of jurisdiction, a bishop can dispense from those prohibent impediments of ecclesiastical law which are not reserved to the pope, and even from such reserved impediments under certain conditions. He may also, under certain conditions, dispense from diriment impediments. Sufficient causes for matrimonial dispensations are divided into canonical causes, i. e. classified and held as sufficient by the common law and canonical jurisprudence, and reasonable causes, i. e. not provided for nominally in the law, but deserving of equitable consideration in view of circumstances or particular cases. Matrimonial nullity Promulgation Promulgation is the act by which the legislator manifests to those subject to his jurisdiction the decision that he has made and makes known to them his intention to bind them to the observance of his law. Without having been promulgated, the canonical law in question has no legal effect, since promulgation is "an essential factor of legislation" and "an absolute condition for the effectiveness of a law". Philosophically it is a matter of dispute whether promulgation is of the essence of a law. It seems indisputable that the essential element of a law is the will of the legislator, but it is clear that the legislator should make known his will and intention in one way or another. This manifestation is the promulgation of the law, which is not necessarily distinct from the very elaboration of the law, provided that this takes place by external acts. Once promulgation takes place, a canonical law acquires its last "essential condition" and takes immediate effect, subject to the vacatio legis imposed by universal law, or by the particular legislator issuing a law (see section below). Promulgation is a "formal and fundamental element" of canon law. For the purposes of canonical jurisprudence, promulgation is equivalent to publication, although the promulgation of a law must not be confounded with its publication, the object of the first being to make known the will