‘Bare delivery of itself never transfers ownership.’
Aulus’s property could only be transferred by two formal methods – mancipatio and cessio. Mancipatio was the primary mode of transferring res mancipi in the ius civile and was regarded as such even before the inception of the Twelve Tables. Both mancipiato and cessio necessitated the transfer of res mancipi in the presence of witnesses.
It is evident that Aulus made a legitimate sale of res mancipi - it would be his duty as dominus to complete the transaction lawfully and his rights to the res mancipi would be transferred to Balbus.
Upon legitimate recipt of the res mancipi, Balbus would have bonitary ownership of the same – not dominium. This means that he would not have the same rights and duties as Aulus. He would not officially own the res mancipi but be in possession of it – this would undeniably affect Balbus’ rights and duties. Since Balbus did not have the title of dominus he would be in a rather precarious position with regard to the ius civile. If Balbus were to be in possession of the said res mancipi for a prescribed period of time, he would acquire the rights and duties of dominus by usucapio. However, Balbus, as a possessor and not an owner then sold and delivered the res mancipi to C (Cornelius). Provided that Balbus complied with the legal requirements of selling and delivering the res mancipi, Cornelius would then adopt the same rights and duties that were attributed to Balbus as possessor.
According to later Roman law, in order to aid his attainment of usucapio, Cornelius as buyer and bonitary owner could add Balbus’ period of possession to his as long as they both bought in bona fide. It is important to note that possession of the res mancipi was protected in Roman law. Remedies were available whereby the possessor could protect his assets – these were know as possessory interdicts. Therefore, when D (Decimus) unlawfully stole the res mancipi, Cornelius had not attained the role of dominus but remained the possessor or bonitary owner.
Decimus obviously had no rights to the res mancipi as he acquired the property unlawfully and without permission from Cornelius. Decimus committed an act of theft – an actio furti or the jurist’s term contrectatio, which denotes any ‘meddling’ or handling of the property in question. As a consequence of his actions, Decimus would be subject to penal action in that Cornelius could recover damages from him and he would also risk being subjected to infamia – which would definitely limit his future rights and subsequent duties.
It appears to be a contentious issue as to who would be allocated the res mancipi. E (Equitius) bought the res mancipi in good faith – bona fides - and therefore thought he possessed the property and was therefore the bona fide possessor. It does appear that Cornelius has a claim in vindicatio to reclaim possession of the res mancipi and so Equitius would have no rights, despite buying and receiving the property in bona fides. Without the actio furti by Decimus, Cornelius would have remained in possession of the res mancipi and, after one or two years of possession, would have become the owner but for Decimus’ actions. Therefore, the praetor would award the res mancipi back to Cornelius, the bonitary owner and Equitius would relinquish all rights and duties to the property acquired, although bought in bona fides, because it was through an actio furti.