PRESUMPTION (Canon Law). - A logical argument whereby, on the basis of the bond of causality that links certain natural and human events to one another, one may deduce the truth or, at least, the probability of the truth of an uncertain fact, consequent upon a fact or upon other facts that are known to us.
One may ask whether presumption, which is certainly one of the means of proof in a trial, is an institution of substantive or of procedural law. As regards the CIC, it seems certain that the answer must be that proof, and consequently presumption, forms part of procedural law: indeed the De praesumptionibus stands in book IV, chap. 2 of title X, De probationibus; and proof is considered in its various subspecies (among which is presumption) only if it is produced by the judge, or evaluated by him. The Code of Civil Procedure of the State of Vatican City (I. I, tit. III: Delle prove) seems partially to follow the concept of canon law illustrated above; it does not expressly contemplate presumptions among the means of proof, but it speaks of them in various places (cf. sec. 3ᵃ, tit. cit., art. 91 § 2 and art. 92 § 1: «La confessione fatta fuori del giudizio ad un terzo costituisce fonte di p. semplice», where the term presumption is expressly employed, and indicates in this case a praesumptio hominis; as in § 1 a praesumptio iuris tantum is contained. The question, therefore, could be called merely doctrinal and not practical as far as canon and Vatican legislation are concerned, whereas for Italian law it is not so: indeed proof and, consequently, presumption are inserted both in the Code of 1865 and in the current one, whereas in the Code of Civil Procedure only the taking of evidence is dealt with. In substance, Italian law distinguishes what proof is and what proof means in a trial: it therefore attributes to proof and to presumption the character of institutions of substantive law.
Presumptions are distinguished into presumptions of law or legal presumptions and presumptions of man or of the judge. Legal presumptions are in turn divided into praesumptiones iuris tantum and praesumptiones iuris et de iure. The difference among the three types of presumption is extremely important: it suffices to bear in mind can. 1826 of the CIC: «Contra praesumptionem iuris simpliciter admittitur probatio tum directa tum indirecta; contra praesumptionem iuris et de iure, tantum indirecta, hoc est contra factum quod est praesumptionis fundamentum». The evaluation of presumptions of man is then left to the judge, who must ascertain the truth of the certain and determined fact from which he draws his persuasion. Proof against a presumption is called direct when the fact is not contested, but instead the consequences that flow from this fact, that is, the presumption of law, are shown to be false. Indirect, on the other hand, is the proof when the fact itself is shown to be false. It is extremely important to note how legal presumptions can invert the burden of proof, which, in theory, belongs to the plaintiff; indeed legal presumptions dispense from any proof the persons for whom they are established; therefore, against an action brought on the basis of a legal presumption, the defendant cannot merely raise an objection, but must prove. Naturally the presumption can also be in favor of the defendant, who puts it forward as an objection against the plaintiff's claim. A clear example of this is found in can. 1015 § 2: «Celebrato matrimonio, si coniuges simul cohabitaverint, praesumitur consummatio, donec contrarium probetur.» Now, one who seeks a dispensation super rato et non consummato has against him the presumption of law, and the Defender of the Bond, defendant in these cases, can limit himself to raising it as an objection.
The CIC establishes only two presumptions iuris et de iure: the impossibility of giving direct contrary proof is a matter of exceptional gravity and therefore the provision of law that establishes a presumption iuris et de iure must be exceptional. Can. 1904 § 1 says thus: «Res iudicata praesumptionem iuris et de iure habetur vera et iusta nec impugnari directe potest». Therefore, the principle being established that a res iudicata does not admit direct contrary proof, the legislator has granted an extraordinary challenge against a judgment that has become final (the restitutio in integrum), which can be invoked only if new documents have been discovered, contrary to the fact on which the judgment itself is based; or if the documents produced at trial and which determined the judge's decision are recognized as false; or if the judgment is the effect of the fraud of one party; or if legis praescriptum evidenter neglectum fuerit. It is evident that in all these cases one does not directly attack the judgment itself, but the presuppositions on which it is based; that is, one must show to be false the facts on which rests the presumption iuris et de iure of the truth of the judgment that has become final. The second presumption iuris et de iure is found in can. 1971: «Matrimonium quod, utroque coniuge vivente, non fuerit accusatum, post mortem alterutriae vel utriusque coniugis ita praesumitur validum fuisse, ut contra hanc praesumptionem non admittitur probatio, nisi incidenter oriatur questio».
Much more numerous are, naturally, the presumptions iuris tantum. Besides the one cited above, dictated by can. 1015, there are others, both express and deducible from the wording of the law. Most important among all is the presumption established in can. 1086 § 1: «Internus animi consensus semper praesumitur conformis verbis vel signis in celebrando matrimonio adhibitis», which means that marriage is presumed valid until proof of its nullity is given. Another important presumption is that of can. 1814: «Documenta publica sive ecclesiastica sive civilia genuina praesumuntur, donec contrarium evidentis argumentis evincatur». Again can. 9 § 2 establishes: «Lex non praesumitur personalis, sed territorialis, nisi aliud consitet». And again: one who is elected to an ecclesiastical office «Recepta confirmatione, electus obtinet plenum ius in officio, nisi aliud in iure caveatur» (can. 177); therefore the one elected is presumed to have the full right over the office, until it can be shown that a particular provision of law stands in the way of this full right. Likewise in a criminal trial, once the inquisitorial phase is completed, one may proceed to the accusation only when the accused is presumed guilty (can. 1946).
As was mentioned, however, presumptiones hominis are not and cannot be cited in the CIC; it is the judge who must draw from certain facts those necessary deductions that must guide him in judging. Naturally, even in the field of presumptiones hominis norms are established, but not by the law, which is in fact foreign to this, but by doctrine and jurisprudence. Indeed, it is possible to determine from the study of many similar facts the consequences that derive from the facts themselves and to determine presumptions that are almost stable, or at least applicable, to a certain group of questions. If matrimonial causes are considered, one can note, for example, that in causes ex capite vis et metus the existence of the metus is presumed from the aversion of the spouse who suffered the coercion toward the other spouse; a greater probability of the existence of the metus is presumed if the metum patiens is of the female sex and is of youthful age, and so on; one observes that in causes of simulation ob exclusum bonum prolis the tenacious will manifested post-matrimonium gives rise to the presumption of the existence of such a tenacious will also in the pre-matrimonial period. These presumptions and many others besides are by now fixed data in matrimonial causes, so much so as to be able to be considered something more than the simple presumptio hominis, deduced case by case by the judge.
Even in civil law presumptions are of the greatest importance, and in Italian law there are very numerous legal presumptions: a presumptio iuris et de iure is that established by art. 232, according to which the child conceived during the marriage is to be considered the child of the husband: in this case the presumption is overcome not by demonstrating the falsity of the presupposition, but the material and physical impossibility of the presupposition itself. A presumptio iuris tantum is that of art. 1141: "Possession is presumed in him who exercises the power of fact, when it is not proved that he began to exercise it simply as detention": in this case, therefore, contrary proof is admitted.