Enrichment by transfer

All the other special enrichment claims are characterized by the fact that the plaintiff tries to reclaim what he has transferred to the defendant. Broadly speaking, the condictio is granted if the purpose which this transfer was intended to attain has either been frustrated or is, for some or other reason, frowned upon by the community.

(a) Transfer solvendi causa

The transfer between plaintiff and defendant has taken place solvendi causa; in particular, the plaintiff may have intended to discharge an obligation created either by stipulation or by a contract of sale. That this obligation did not in fact exist, was not, as a rule, of any consequence as far as the transfer of ownership from plaintiff to defendant was concerned. Mancipatio and in iure cessio were "abstract", anyway; and tradirio, though "causal",⁵⁰ did not depend on the validity of the underlying stipulatio or emptio venditio. In other words: the fact that performance was rendered solutionis causa was in itself sufficient as a iusta causa traditionis.⁵¹ An exception existed only in so far as the vendor's performance was not regarded as solutio.⁵² As a result, therefore, a promisor who transferred ownership in either money or any other object, or a purchaser who paid the purchase price, lost their ownership on account of such a transfer, even if the stipulation or contract of sale were invalid.⁵³ Thus, the rei vindicatio was of no avail, and a remedy was required to enable the promisor or ^{[4333] [4334] purchaser to claim retransfer of ownership. This remedy was the condictio indebiti. The vendor, on the other hand, who handed over the object of the sale, retained his ownership if the contract of sale turned out to be defective.}

(b) Executed transactions

Where a contract of sale was concluded and executed at one and the same time (executed sale), the transfer could not be said to have been made solvendi causa: there was no pre-existing obligation which the performance was supposed to discharge. Thus, it was the causa emptionis, or causa venditionis, itself upon which the effect of the traditio depended; and, as a result, ownership did not pass if the contract of sale was in any way defective. Again, no condictio was required.^[4335] The same applied where a transfer was made donationis causa or by way of datio dotis.^[4336]

(c) Transfer credendi causa

If a sum of money was handed over credendi causa (that is, as a loan for consumption), ownership remained with the lender if the contract of mutuum turned out to be invalid.^{[4337] [4338] Only consumptio nummorum on the part of the recipient could change the situation:" the rei vindicatio was then replaced by a condictio; not, however, by one of those based on a transfer.[4339]}

(d) Datio oh rem

Not rarely did it happen that someone made a performance in order to elicit some form of counterperformance on the part of the recipient. Unless the recipient became bound to render such a counterperfor­mance (that is, unless a contract had come into existence), the transferor required some form of protection, in case his expectations were disappointed. Being unable to enforce the counterperformance, he had to be able to reclaim his own performance and was therefore duly granted a condictio. Since his transfer was usually referred to as datio ob rem (transfer for a purpose envisaged),^[4340] this particular form of condictio was called condictio ob rem. Rather confusingly, it also came to be referred to as condictio ob rem dati, ob causam datorum and causa data causa non secuta.^[4341] It was the last name^[4342]' which Justinian decided to use in the Digest.

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