[IDEM libro uicesimo quinto digestorum. ] §18.4.19.prMultum interest, sub condicione aliqua obligatio ueneat an, cum ipsa obligatio sub condicione sit, pure ueneat.
[THE SAME, Digest, book 25.] is a great difference between whether some obligation is sold under a condition, or whether, when the obligation itself is conditional, it is sold unconditionally.
priore casu deficiente condicione nullam esse uenditionem, posteriore statim uenditionem consistere: nam si Titius tibi decem sub condicione debeat et ego abs te nomen eius emam, confestim ex empto uendito agere potero, ut acceptum ei facias.
In the former case, if the condition fails, there is no sale; in the latter, the sale is established immediately. For if Titius owes you ten under a condition and I buy his debt from you, I will be able to bring an action on purchase and sale immediately, so that you may grant him a release.