IN LAW. — The term is found in the Roman legal sources, and not only to indicate the final part, but also a section, or a body of provisions, of the praetor’s edict concerning a specific subject (clausula edictalis).
Hence the twofold meaning that the term has in ordinary legal language. By c. is meant both a section or article that forms the content of a legal transaction (c. contrattuale, c. testamentaria), and, in the strict sense, a provision expressed in a brief, significant formula sanctioned by usage, which is inserted into an act (as a rule, as an appendix) in order to give it a particular extending or limiting effect.
Thus, for example, in Roman law there is the c. codicillaris, intended to ensure that a will, even if declared invalid as such, may at least have validity as a codicil; likewise, in modern obligations law, there are the c. penale, the c. compromissoria, the c. rebus sic stantibus, the c. di concorrenza, and so forth; and, outside the field of private law, the c. provvisionale (CIC, can. 1917 § 2), the c. della nazione più favorita, etc.
In attempting a systematic classification of the c. most frequently used in canon law (the older treatises give interminable lists of them), it may be said that, with regard to the source from which the acts originate, they are distinguished into clausulae communes, those customarily appended to contracts, wills, judicial acts of parties, etc.; and clausulae apostolicae, proper to acts of the pontiff.
The notion of c. in canon law is of particular importance to the doctrine of rescripts (v.), where, however, the term is used interchangeably with the term condition in the broad sense, to signify both the circumstances essential to the validity of the rescript (e.g., the c. or condition «si preces veritate nitantur», which must in any event be understood), and accidental and modal circumstances, such as commands and admonitions (clausulae mere praeceptivae), and instructions, commonly addressed to the executor of the rescript (clausulae instructivae), non-compliance with which, although undoubtedly constituting an unlawful act, is nevertheless lacking in the sanction of the nullity of the rescript.
But this notion, developed in the matter of rescripts and certainly not limited solely to them, does not exhaust, as has been seen and as will also be seen, the entire concept of c. in the strict sense.
In general, from the standpoint of content, two categories of c. may in fact be distinguished: those with merely positive content, which establish the conditions for the validity of the act, determine its efficacy (e.g., the c. «rebus sic stantibus») and its modalities; and those with negative content, consisting in provisions extending or limiting the efficacy of the act itself, in derogation from the rules of common law (clausulae derogatoriae).
The following belong in this second category: a) the c. by which a pre-existing legal situation is modified through the abrogation of rules or the revocation of concessions (clausulae abrogatoriae, revocatoriae); in this regard, one may recall the customary formulas «revocatis vel non obstantibus...»; b) those intended to prevent the formation of a possible legal situation (clausulae prohibitoriae), as, for example, in the formula «exclusa in futuro qualibet consuetudine contraria»; c) those that limit the normal efficacy of the act in time (clausulae peremptoriae); d) finally, those that preserve the act from possible challenges by confirming it in advance (clausulae praedictales).
As regards the interpretation of the c., for the purpose of determining their effects, there can obviously be no certain general rule. With regard to the first category (c.-conditions), the CIC offers, in can. 39, a formalistic criterion which, although laid down for rescripts, should also be extended to other acts and, by analogy,
to laws: conditions are presumed essential to the validity of the act when they are expressed by the particles si, dummodo, or another equivalent term.
As for the other category, the meaning and efficacy of some of the most frequently used c. are determined in some cases by the CIC itself, and in others by doctrine.
Thus, for example, by means of the peremptory c. «ad beneplacitum nostrum» (v.) or another equivalent formula (e.g., «donec voluero», but not «donec revocavero» or «usque ad revocationem» or «ad beneplacitum Ordinarii pro tempore», «ad beneplacitum Sedis»), the efficacy of the rescript is limited in time; this efficacy normally continues even resoluto iure concedentis (cf. can. 73, in relation to can. 61); by means of the c. «motu-proprio» (can. 45), the invalidity of the rescript resulting from the concealment of truths deemed necessary is remedied (and this in derogation from the principle laid down in the preceding cann. 40 and 42), since it is presumed that, through the adoption of the aforesaid c., the will expressed in the rescript has become independent of the motivating causes set out in the petition; by means of the clausulae praedictales maiores (c. «ex certa scientia», «sublata», «decretum irritans», etc.), the mouth is closed and the hands are tied, to use the characteristic expression of Cardinal De Luca, of the judge and the parties, that is, the cognizance of any challenge to the act is withdrawn from every other judge who is not the Roman pontiff himself.