As it was mentioned in the previous section140, the Roman sources often use
expressions such as potestas alienandi or ius vendendi to succinctly declare that someone may be entitled to transfer ownership. However, the existence of such expressions does not imply that Roman jurists would generally declare that one of the requirements for the transfer of ownership is the potestas alienandi of the
tradens. Instead, Roman sources usually have as a more simple starting point that
the tradens must be owner141. To name just a few: D. 18,1,74 declares that if the
transferor is not the owner usucapion will start at once142, which implies that
ownership is not transferred; D. 41,1,20pr and D. 50,17,54143 categorically
establish that one cannot transfer what one does not have, which in the first text means that only the owner can transfer ownership; D. 18,1,28144 determines that
the sale by a non-owner is valid as such, but that it will not transfer ownership. Particularly interesting is moreover the opening text of Gaius dealing with the transfer of ownership by traditio:
Gai 2,18-20: (18) Magna autem differentia est inter mancipi res et nec mancipi. (19) Nam res nec mancipi ipsa traditione pleno iure alterius fiunt, si modo corporales sunt et ob id recipiunt traditionem. (20) Itaque si tibi vestem vel aurum vel argentum tradidero sive ex
140 Chapter 1, Section 2(a).
141 Whether he must be a dominus ex iure Quiritium will be discussed in the following sections.
142 D. 18,1,74 (Pap. 1 def.): “Clavibus traditis ita mercium in horreis conditarum possessio
tradita videtur, si claves apud horrea traditae sint: quo facto confestim emptor dominium et possessionem adipiscitur, etsi non aperuerit horrea: quod si venditoris merces non fuerunt, usucapio confestim inchoabitur”. See on this text Miquel, Contrato real abstracto (2003), p. 5764.
143 See on this text Chapter 6 below.
144 D. 18,1,28 (Ulp. 41 Sab.): “Rem alienam distrahere quem posse nulla dubitatio est: nam
OWNERSHIP AND POTESTAS ALIENANDI, SYSTEMATIC CONSIDERATIONS the alienation by a non-owner should be performed nomine alieno, resorts to the
rules concerning the acquisition through a third party and concludes that it is relevant that the agent acts on behalf of the dominus negotii. In this case the analogy between the acquisition and transfer of ownership appears once again to be inadequate, since the need to act nomine alieno has a specific ground in the context of the acquisition of possession which is completely absent in order to transfer ownership136. These problems will be studied in further detail in the
following chapters.
A similar problem to that of the acquisition by a third person takes place regarding the payment done by someone who is not the debtor, which is often studied closely to the transfer of ownership by a non-owner137. One may
understand that both problems could be set side by side, since they could even coincide in a specific case, such as the payment carried out by a third person who pays with the owner’s money and following his instructions. In such case, the non-owner would be simultaneously transferring ownership and paying a debt which is not his own. Nonetheless, most of the discussion of the payment by a non-owner falls outside the problem of the transfer of ownership by a non- owner, since the most controversial cases are precisely those in which the third person pays with his own money and without the owner’s authorization. In such cases, as noted above138, Roman jurists would offer a solution which was only
applicable to cases in which the owner derives a benefit from the conduct of the third person, namely that the act conducted by the latter would directly affect his position even if he had not authorized it. The solution is completely different regarding the cases in which the owner would suffer a patrimonial loss as a result of the acts of the non-owner. In such situations the owner’s authorization was indispensable, as highlighted by Gaius in D. 3,5,38(39)139. Accordingly, just as in
the case of the acquisition by a non-owner, the payment by a non-debtor cannot be regarded as an institution closely linked to the transfer of ownership by a non- owner, being in fact approached by Roman jurists as an opposite problem, in which the principal does not lose something, as happens in the traditio, but rather becomes richer.
It is important to keep in mind the fundamental distinction between the way the solutio by a non-debtor and the traditio by a non-owner operate in order to avoid extrapolating to the transfer of ownership features which only apply to the payment. This is particularly the case regarding the need to act nomine alieno. In the case of the payment by a third person, it is of course essential that he indicates precisely whose debt is he paying, in order that this precise debt is extinguished.
136 See Buckland, Main institutions (1931), p. 170.
137 Regarding the payment by a procurator see Apathy, Procurator und solutio (1979), p. 65-88.
138 Chapter 1, Section 2(b).
139 Chapter 1, Section 2(b) above. The idea according to which one may pay without the
knowledge or authorization of the debtor is also laid down in D. 46,3,53 (Gai. 5 ad edictum
provinciale) and Inst. 3,29pr.
The main texts dealing with the payment by a third person stress that the knowledge or authorization of the debtor is not needed for the validity of the payment, it being however essential that he acts on behalf of the debtor. When conveying this solution it is explicitly indicated that this applies to the cases where the condition of the principal is improved by the acts of the third person, and not to those where his patrimony is diminished, as happens with the delivery of his ownership. Accordingly, peculiar features of the payment by a non-owner such as the need to act nomine alieno cannot be considered to apply instantly to the problem of the transfer of ownership by a non-owner.
3. Ownership and potestas alienandi, systematic considerations
As it was mentioned in the previous section140, the Roman sources often use
expressions such as potestas alienandi or ius vendendi to succinctly declare that someone may be entitled to transfer ownership. However, the existence of such expressions does not imply that Roman jurists would generally declare that one of the requirements for the transfer of ownership is the potestas alienandi of the
tradens. Instead, Roman sources usually have as a more simple starting point that
the tradens must be owner141. To name just a few: D. 18,1,74 declares that if the
transferor is not the owner usucapion will start at once142, which implies that
ownership is not transferred; D. 41,1,20pr and D. 50,17,54143 categorically
establish that one cannot transfer what one does not have, which in the first text means that only the owner can transfer ownership; D. 18,1,28144 determines that
the sale by a non-owner is valid as such, but that it will not transfer ownership. Particularly interesting is moreover the opening text of Gaius dealing with the transfer of ownership by traditio:
Gai 2,18-20: (18) Magna autem differentia est inter mancipi res et nec mancipi. (19) Nam res nec mancipi ipsa traditione pleno iure alterius fiunt, si modo corporales sunt et ob id recipiunt traditionem. (20) Itaque si tibi vestem vel aurum vel argentum tradidero sive ex
140 Chapter 1, Section 2(a).
141 Whether he must be a dominus ex iure Quiritium will be discussed in the following sections.
142 D. 18,1,74 (Pap. 1 def.): “Clavibus traditis ita mercium in horreis conditarum possessio
tradita videtur, si claves apud horrea traditae sint: quo facto confestim emptor dominium et possessionem adipiscitur, etsi non aperuerit horrea: quod si venditoris merces non fuerunt, usucapio confestim inchoabitur”. See on this text Miquel, Contrato real abstracto (2003), p. 5764.
143 See on this text Chapter 6 below.
144 D. 18,1,28 (Ulp. 41 Sab.): “Rem alienam distrahere quem posse nulla dubitatio est: nam
venditionis causa sive ex donationis sive quavis alia ex causa, statim tua fit ea res, si modo ego eius dominus sim.145
The basic rule is clear: the delivery which follows a iusta causa will transfer ownership if it is done by the owner of the delivered thing, and it will not transfer ownership if performed by a non-owner. The owner alone has the power to alienate. Moreover, when discussing the acquisition through usucapion, Gaius shows once again that it is essential for the transfer of ownership that the transferor is the owner. This is in turn emphasized by the description of the content of the good faith of the acquirer as the belief that it was the owner who performed the traditio:
Gai 2,43: Ceterum etiam earum rerum usucapio nobis conpetit, quae non a domino nobis traditae fuerint, sive mancipi sint eae res sive nec mancipi, si modo eas bona fide acceperimus, cum crederemus eum, qui tradet, dominum esse.146
All of these texts could give the impression that for Roman jurists only the true owner would be able to transfer ownership. However, several other texts, while maintaining as the basic starting point that the transferor must be owner, introduce further clarifications which narrow down in a more accurate way the requirements to transfer ownership. Particularly eloquent in this regard is Gai 2,62-64, which is introduced with the phrase: “Accidit aliquando, ut qui
dominus sit, alienandae rei potestatem non habeat, et qui dominus non sit, alienare possit”147. The wording of the text shows that we are dealing with cases which
depart from the general rule, since it “sometimes happens” that someone different than the owner can transfer ownership, or that the owner cannot transfer ownership. The starting point or general rule is clearly that the tradens must be owner, but this notion can be subject to clarifications148. Miquel stressed
that the text of Gai 2,62-64 should therefore be interpreted as the last part of a sequence of texts, narrowing down the general notions laid down in Gai 2,20
145 Gai 2,18-20: “(18) Now, there is a great difference between res mancipi and nec mancipi. (19)
For res nec mancipi become the full property of someone else by the very act of delivery, provided that they are corporeal and so capable of delivery. (20) And so, if I deliver to you clothing or gold or silver, whether on the basis of a sale or a gift or on any other basis, it immediately becomes yours, provided that I am owner of it” (transl. Gordon/Robinson, modified).
146 Gai 2,43: “But we can also usucapt things which have not been delivered to us by the
owner, whether they are mancipi or nec mancipi, provided that we receive them in good faith, in the belief that the person who delivered them was owner” (transl. Gordon/Robinson).
147 Gai 2,62: “It sometimes happens that an owner does not have power to alienate and that a
non-owner does” (transl. Gordon/Robinson).
148 Buckland, Interpolations (1941), p. 1309; Zulueta, Institutes of Gaius (1953) II, p. 74;
Potjewijd, Beschikkingsbevoegdheid (1998), p. 9-10.
and Gai 2,43, according to which the transferor should be the owner149.
Gai 2,62-64 ends the general analysis of the acquisition of ownership by traditio and usucapion with a more accurate criterion which narrows down the previous general statements on the subject.
While discussing the systematic role of Gai 2,62-64, it must be pointed out that the position of this fragment within the work of Gaius was a controversial matter in the editing history of the Institutes. The first editions located the passage in its current place150, following the original order of Gaius’ exposition,
where the text is divided between f. 102v and f. 85r of the Veronese palimpsest151. In 1834, however, Heimbach pointed out that the location of this
fragment could be questioned for two reasons152. First of all, the topic seemed to
be intimately related to the alienations by the mulier and pupillus located in Gai 2,80-85. Therefore, it would be more reasonable to place Gai 2,62-64 before Gai 2,80-85. Additionally, Heimbach argues that the words “Ergo ex his quae
diximus” at the beginning of Gai 2,65 could be properly referred to the topics
covered in Gai 2,22-61, but would not fit with the additional topic of Gai 2,62- 64. Heimbach’s considerations were accepted by Huschke153, who adds as an
additional argument that the topics dealt with in Gai 2,62-64 and Gai 2,80-85 are set side by side in the Institutes of Justinian (Inst. 2,8, “Quibus alienare licet vel
non”). According to Huschke, the juxtaposition of these texts in Justinian’s
Institutes would in this way demonstrate the original order of Gaius’ text.
The opinion of Heimbach and Huschke found some initial resistance, being criticized by Böcking154 in his first editions of the Institutes. It was also refuted by
Mommsen in his Epistula Critica which precedes the first edition of the Institutes by Krüger and Studemund155. Mommsen considered that Gai 2,62-64 was related
149 Miquel, Compraventa y transmisión (1993), p. 101-107; Miquel, Traditio rei alienae (1993),
p. 272-273.
150 Göschen, Gaii Institutionum (1820), p. 91-92; Lachmann, Gaii Institutionum (1841), p. 69-
70.
151 See the recent photomechanical reproduction of the manuscript in Briguglio, Gai Codex
Rescriptus (2012), p. 229 and 266.
152 Heimbach, Ueber Ulpians Fragmente (1834), p. 34-35.
153 Huschke, Iurisprudentiae anteiustinianae (1861), p. 149, n. 42. This opinion is maintained in
later editions of his Iurisprudentiae anteiustinianae: cfr. Huschke, Iurisprudentiae anteiustinianae (1867), p. 159-160, n. 45; Huschke, Iurisprudentiae anteiustinianae (1886), p. 234 n. 5 already records Mommsen’s observation (quidquid Mommsenus commendandi vel excusandi eius gratia in ed. Kr. 2 contra dicat) but does not accept it. Only in the posthumous sixth edition by Seckel and Kübler (Huschke/Seckel/Kübler, Iurisprudentiae
anteiustinianae [1903], p. 66) did the fragment return to its traditional position.
154 Böcking, Gaii Institutionum (1841), p. 65 n. 1.
155 Krüger/Studemund, Gai Institutiones (1877), p. XIX-XX, now in Mommsen, Emendationes
Gaianae (1905 [1877]), p. 41-42: “Displicet transpositio Heimbachiana. Gaiana dispositio
commoda magis quam accurata hic eo nititur, quod primum agitur de rerum alienatione, ad quem tractatum usucapio quoque redigitur utpote iustae alienationis legitimum supplementum, deinde transitur ad rerum adquisitionem eam, quae non ab alienatione pendet, qualis est occupatio et specificatio. Locus autem, quaenam res recte alienentur a non domino vel alienari nequeant a domino, aperte prioris tractatus appendix est, quo ipso
OWNERSHIP AND POTESTAS ALIENANDI, SYSTEMATIC CONSIDERATIONS venditionis causa sive ex donationis sive quavis alia ex causa, statim
tua fit ea res, si modo ego eius dominus sim.145
The basic rule is clear: the delivery which follows a iusta causa will transfer ownership if it is done by the owner of the delivered thing, and it will not transfer ownership if performed by a non-owner. The owner alone has the power to alienate. Moreover, when discussing the acquisition through usucapion, Gaius shows once again that it is essential for the transfer of ownership that the transferor is the owner. This is in turn emphasized by the description of the content of the good faith of the acquirer as the belief that it was the owner who performed the traditio:
Gai 2,43: Ceterum etiam earum rerum usucapio nobis conpetit, quae non a domino nobis traditae fuerint, sive mancipi sint eae res sive nec mancipi, si modo eas bona fide acceperimus, cum crederemus eum, qui tradet, dominum esse.146
All of these texts could give the impression that for Roman jurists only the true owner would be able to transfer ownership. However, several other texts, while maintaining as the basic starting point that the transferor must be owner, introduce further clarifications which narrow down in a more accurate way the requirements to transfer ownership. Particularly eloquent in this regard is Gai 2,62-64, which is introduced with the phrase: “Accidit aliquando, ut qui
dominus sit, alienandae rei potestatem non habeat, et qui dominus non sit, alienare possit”147. The wording of the text shows that we are dealing with cases which
depart from the general rule, since it “sometimes happens” that someone different than the owner can transfer ownership, or that the owner cannot transfer ownership. The starting point or general rule is clearly that the tradens must be owner, but this notion can be subject to clarifications148. Miquel stressed
that the text of Gai 2,62-64 should therefore be interpreted as the last part of a sequence of texts, narrowing down the general notions laid down in Gai 2,20
145 Gai 2,18-20: “(18) Now, there is a great difference between res mancipi and nec mancipi. (19)
For res nec mancipi become the full property of someone else by the very act of delivery, provided that they are corporeal and so capable of delivery. (20) And so, if I deliver to you clothing or gold or silver, whether on the basis of a sale or a gift or on any other basis, it immediately becomes yours, provided that I am owner of it” (transl. Gordon/Robinson, modified).
146 Gai 2,43: “But we can also usucapt things which have not been delivered to us by the
owner, whether they are mancipi or nec mancipi, provided that we receive them in good faith, in the belief that the person who delivered them was owner” (transl. Gordon/Robinson).
147 Gai 2,62: “It sometimes happens that an owner does not have power to alienate and that a
non-owner does” (transl. Gordon/Robinson).
148 Buckland, Interpolations (1941), p. 1309; Zulueta, Institutes of Gaius (1953) II, p. 74;
Potjewijd, Beschikkingsbevoegdheid (1998), p. 9-10.
and Gai 2,43, according to which the transferor should be the owner149.
Gai 2,62-64 ends the general analysis of the acquisition of ownership by traditio and usucapion with a more accurate criterion which narrows down the previous general statements on the subject.
While discussing the systematic role of Gai 2,62-64, it must be pointed out that the position of this fragment within the work of Gaius was a controversial matter in the editing history of the Institutes. The first editions located the passage in its current place150, following the original order of Gaius’ exposition,
where the text is divided between f. 102v and f. 85r of the Veronese palimpsest151. In 1834, however, Heimbach pointed out that the location of this
fragment could be questioned for two reasons152. First of all, the topic seemed to
be intimately related to the alienations by the mulier and pupillus located in Gai 2,80-85. Therefore, it would be more reasonable to place Gai 2,62-64 before Gai 2,80-85. Additionally, Heimbach argues that the words “Ergo ex his quae
diximus” at the beginning of Gai 2,65 could be properly referred to the topics
covered in Gai 2,22-61, but would not fit with the additional topic of Gai 2,62- 64. Heimbach’s considerations were accepted by Huschke153, who adds as an
additional argument that the topics dealt with in Gai 2,62-64 and Gai 2,80-85 are set side by side in the Institutes of Justinian (Inst. 2,8, “Quibus alienare licet vel
non”). According to Huschke, the juxtaposition of these texts in Justinian’s
Institutes would in this way demonstrate the original order of Gaius’ text.
The opinion of Heimbach and Huschke found some initial resistance, being criticized by Böcking154 in his first editions of the Institutes. It was also refuted by
Mommsen in his Epistula Critica which precedes the first edition of the Institutes by Krüger and Studemund155. Mommsen considered that Gai 2,62-64 was related
149 Miquel, Compraventa y transmisión (1993), p. 101-107; Miquel, Traditio rei alienae (1993),
p. 272-273.
150 Göschen, Gaii Institutionum (1820), p. 91-92; Lachmann, Gaii Institutionum (1841), p. 69-
70.
151 See the recent photomechanical reproduction of the manuscript in Briguglio, Gai Codex
Rescriptus (2012), p. 229 and 266.
152 Heimbach, Ueber Ulpians Fragmente (1834), p. 34-35.
153 Huschke, Iurisprudentiae anteiustinianae (1861), p. 149, n. 42. This opinion is maintained in
later editions of his Iurisprudentiae anteiustinianae: cfr. Huschke, Iurisprudentiae anteiustinianae (1867), p. 159-160, n. 45; Huschke, Iurisprudentiae anteiustinianae (1886), p. 234 n. 5 already records Mommsen’s observation (quidquid Mommsenus commendandi vel excusandi eius gratia in ed. Kr. 2 contra dicat) but does not accept it. Only in the posthumous sixth edition by Seckel and Kübler (Huschke/Seckel/Kübler, Iurisprudentiae
anteiustinianae [1903], p. 66) did the fragment return to its traditional position.