b. Scotus’ own Solution

32. I say, therefore, to this article [n.18] that a slave can, by the will of his master, contract matrimony; and if the burden of matrimony be something repugnant to the accustomed services, the master, by letting him contract, implicitly relaxes the accustomed services for him. And if the master afterward revoke the concession (as by totally preventing him from carnal union or sending him to far-off parts or detaining him in labors so that he cannot visit his spouse sometimes), he would commit mortal sin, and also he would manifestly have to be corrected by the Church.

33. A slave can also contract against his master’s will insofar as he has some right over his own body; for he has not deprived himself of all liberty for all acts; and insofar as his body is his, he can make exchange with another. But if the other, whether slave or free, wish to be content with the modest liberty or power for a modest use that he knows he [the master] can give, he can well make the judgment beforehand for himself, and the exchange stands. And he does have so much power over his body when he is not occupied in the service of his master, if he contract against the master’s will; and then between such [contracting parties] there is only obligation to as much as they can give their bodies to, the master’s justice being preserved. Hence the chapter that does allow slaves to contract, Gregory IX, Decretals IV tit.9 ch.1 ‘On Marriage of Slaves’, says that a slave, if he have contracted against his master’s will, has given what he had, and is bound to fulfill his services to the master, because he cannot give to another save what he had in his power; but he did not have power simply over his body;     therefore etc     .

34. And from this follows that the slave could contract matrimony with a free woman, provided however she know his condition and to him in such condition, because then she exchanges the power of body that she has for the little that the slave has of power over his own body. And he can make a contract with a slave girl, and then it seems that both concede what they can; and as they contract so are they bound, according to justice, to render the debt, namely insofar as those acts do not hinder them from their accustomed services.

35. But let it be that in such a case, when they contract matrimony against the will of the master, one of the masters sends his slave to Africa and the other sends his slave girl to France, is it really licit to do this?

36. I say that, because a case of matrimony is a favorable thing, the masters would have to be induced not to do this; but if they did do it, it is not apparent how, on the supposition of slavery, they would be acting there against justice; because this slave was before in the power of the master to send him thither, indeed to sell him; and that slave girl was likewise in the power of her master as to some other place; and they were not able through their own acts, without the will of their masters, make themselves freer, nor exempt themselves more from the right of their masters than they were before; therefore it is still licit.

37. But if a slave girl intend to contract with him whom she believes to be free and yet he is a slave, does she really contract?

It could be said that error of worse condition does impede the contract, because it prevents the exchanger from receiving as much as that for which they intend to make the exchange; but ignorance of better or equal condition does not impede, for the same reason.