The liability of the mandator

(a) Utility considerations

The fact that mandatum was gratuitous and that the mandatary usually acted in the interest of the mandator may also be expected to have played a role as far as the determination of liability in the reverse direction was concerned: could the mandatarius sue the mandator for any loss — not attributable to the fault of either of the parties—that he had suffered as a result of carrying out the mandate? Yes, is the answer given by lulianus.^[2184] If A, at the request of B, purchases a slave, and this slave, before he can be transferred to B, steals some of A's property, A can recover his full damages from B under the actio mandati (contraria) ("damnum praestari debere").

(b) Casus a nullo praestan tur

But the utility principle is not a hard-and-fast rule of law. It is based on considerations of equity. Furthermore, in the case of mandatum it is not always a realistic guideline for allocating risks and determining standards of liability: the mandatarius, as we have seen, did not necessarily act (solely) in the mandator's interest, and he might well receive a remuneration for his services. It is not surprising, therefore, that the question was controversial amongst the Roman jurists, and that in some of our texts we find a different assessment of the equities of the situation.

"Exceptione, quae tibi prodesse debebat, usus iniuria iudicis damnatus es: nihil tibi praestabitur iure mandati, quia iniuriam, quae tibi facta est, penes te manerc quam ad alium transfem aequius est."^{[2187] [2188] [2189] [2190] [2191] [2192]'}

A stood surety for B.

(c) The ins commune

Since the Middle Ages, jurists and (later) legislators have battled with this problem — and particularly with the confusing state of the sources — and have tried to apply and generalize either Julian's or Paul's view. Thus, for instance, during the 19th century the latter prevailed: the mandator was to be liable for dolus and culpa but not for casus.^[2194] This was in accordance with the general emphasis of the pandectists on fault. § 670 BGB appears to proceed from the same premise, for it grants the mandatary a claim only for outlays incurred in the course of carrying out the mandate, not for damages suffered.^[2195] This means that damages may be claimed only according to general principles, that is, if there was fault on the part of the debtor.

However, over the centuries many writers took the opposite view. "Nee hie § de curialitate debet servari" says, for instance, the gloss apropos Paul. D. 17, 1, 26, 6,^[2196] which is very similar to what, some centuries later, Groenewegen stated the Roman-Dutch law to be.^[2197] Voet, after pointing out that Roman law required fault on the part of the mandator and did not otherwise allow the mandatarius to recover his loss, simply said: "Sed hodie mandatario ex aequitate hie quoque succurendum putant."^[2198] But did this mean that the mandator bore the full risk, including any kind of casus fortuitus? The most interesting and, in the long run, influential criterion for limiting the mandatarius' liability appeal's to have had its origin in the Rationalia ad Pandectas of Antonius Faber, where he grants the claim only for those damages which the mandatarius suffered ex causa mandati.^[2199] The natural lawyers elaborated this idea more fully and distinguished between loss sustained ex causa mandati or merely ex occasione mandati.

"Idem quoque dicendum videtur", wrote Pufendorf, *-*^[2200] "de damno in quo quis ex causa rei mandatae incidit: non tamen de illo, in quo tantum ex occasione eiusdem prolapsus cst. adeoque ilia dumtaxat damna erunt a mandante sarcienda, quae proprie ex ipsa negotio mandate profluxere: non autem, quae vclut transversim intercurrerunt, dum negotium istud obitur."

This distinction found its way into the ABGB^[2201] and also, probably via Pothier,^[2202] into the code civil (although, strangely, the wrong way round).¹⁴⁷ We also find it in modern German law, where the narrow confines of § 670 BGB were soon left behind by courts and legal writers.^lw The principle of a liability (not based on fault) for risks arising from and connected with activities undertaken by another person in the debtor's interest, is widely acknowledged today.¹⁴⁴ "Ex occasione mandati" therefore refers to what one could call the general risks of life, which must, as usual, be borne by the gestor himself. He can therefore not claim damages for an accident which is not specifically related to the gestio, even though it may be causally linked to it.