Natural Rights on the Threshold of the Scottish Enlightenment. Gershom Carmichael

some particle of their natural liberty to others; and are equally correctly said to be abolished by the opposite actions, by which men cease to be obligated in that way, when the particle of liberty which they had alienated is restored to them.

      We therefore had good reason to say that the creation and abolition of personal rights as such, no less than their transmission in the same kind (as also in the case of real rights), lies in a form of transfer. And, apart from some modes of transfer which are irrelevant to the present subject, every transfer is very naturally initiated, as we have said, by mutual consent, by a declaration of appropriate signs on the part of the transferor and of the recipient of the right.

      This mutual act seems to take four different forms, depending on the type of right which is being transferred or its circumstances. In the case of real rights, it is always one and the same, carrying in itself from one subject to another the mere transmission of the rights which relate to its immediate object on both sides (see however what we say below at pp. 101–2).⁴ In the case of personal rights, it may produce three possible effects: (1) a right which was previously contained in the natural liberty of the transferor has been transferred to another man and now belongs to him as a personal right against the first party; in this case a new personal right and corresponding obligation are created for the first time. Or, (2) a personal right which previously belonged to the transferor against a third party has been transferred to someone else and now belongs to him against the same third party; here we see the transfer of a personal right of that particular kind. Or, (3) a personal right which previously belonged to the transferor against the recipient is transferred, or rather restored, to him and consolidated with his natural liberty; and in this case the personal right, as such, and the corresponding obligation are extinguished.

      Each of these acts can be performed either unilaterally, with the effect that a right is transferred from one party and merely acquired by the other, or reciprocally, with the effect that a right is transferred by both parties and received by both of them against each other, and the transfer would not be understood to be fully and validly effected without the other. Thus from these various combinations of acts of the same or of different kinds, arise several kinds of reciprocal acts; some of these have specific names given them in law and popular usage, while others have not.

      As for the term pactum, or “agreement,” this stands for a variety of ideas which do not all have the same extension. The definition of pactum given by Ulpian, Digest, II.14.1.2⁵ is the concurrence of two or more persons in the same intent; Ulpian also appends to the same law (sec. 3) that the explanation of the term conventio is that men from different motions of the mind consent to one thing, i.e., arrive at one opinion. If we look at the proper meanings of the words, both these definitions seem to apply to all the types of mutual acts we have just enumerated. But we admit that the commonest usage is to apply the term pactum, or “agreement,” almost exclusively to acts which are obligatory on at least one side, i.e., acts by which a new personal right is given, as we explained above; and that is how our author seems to understand it.

      Titius defines pactum, or “agreement,” as something done by the consent of two or more, given for the purpose of licitly creating or abolishing an obligation; and therefore includes under the term “agreement” not only acts consisting in the mutual consent by which personal rights are created, but also those by which they are abolished.⁶ But I do not think that we apply the word “agreements” to acts by which personal rights and corresponding obligations are abolished, more than to acts by which rights, whether real or personal, are transmitted from one person to another. It is irrelevant to our purpose as being a matter merely of arbitrary law, that the Roman jurisconsults and their interpreters used this term almost exclusively of acts which create by themselves only a natural and not also a civil obligation unless confirmed by a civil law, and on this ground distinguished them from contracts. [I.9.1.i]

       Promises and agreements; two senses of agreement

      We have just said that in his first paragraph⁷ our author understands by the term pactum, or “agreement,” an act consisting in mutual consent which is obligatory on at least one side. Now in this paragraph⁸ he restricts the word to one species within that genus, namely, that which is obligatory on both sides. However it should be noted, that if by the division here proposed a distinction is made in the case of an act obligatory by mutual consent, between one which creates obligation on one side only and one which creates obligation on both sides, the former is not well named a gratuitous promise. For there are acts which are obligatory on one party only, and which nevertheless, can by no means be called gratuitous promises, since they include from the other party, either some transmission of right, as in loan for consumption (mutuum) (where the term implies that the receiving party in this transaction is obligating himself to the giver, because the latter is at the same time transferring to him the ownership of the money given by mutuum), or the cession or remission of a right which was previously valid against the party creating the obligation, as is often the case in transactions.⁹ However if you are willing to understand by the term pactum, or “agreement,” in its narrower sense, a mutual act by which an obligation is contracted by at least one party (or, which is the same thing, by which a man transfers a personal right to be valid against himself), and in return a right of some kind is transferred by the other party, then pactum, or “agreement,” in its broader sense is rightly divided into gratuitous promise and pactum in the special sense. [I.9.5.i]

       [Grotius distinguished agreements based upon mere declarations of intent and the necessity of keeping faith from perfect agreements, where there is a clear sign that a right is to be conferred (Grotius, Rights of War and Peace, II.XI, p. 281 ff). Pufendorf applied this distinction specifically to promising (Pufendorf, Of the Law of Nature and Nations, III.V.6, p. 269; Pufendorf, On the Duty of Man and Citizen, I.9.6, pp. 69–70). Carmichael comments:]

      The authors apply this distinction of perfect and imperfect to promises rather than to agreements in general, perhaps because every reciprocal agreement is perfect in the state of nature. I say, in the state of nature; for in civil society, only those agreements and promises which may be enforced in the courts by an action taken under civil law are considered perfect. And just as a perfect promise confers a perfect right, I do not see why an imperfect right should not follow from an imperfect obligation. [I.9.6.i and ii]

      “Error” in promises and agreements

      [In Roman law promises and agreements are frustrated by various forms of error, fraud, or force which occur in the making of them. In all these categories Carmichael allows fewer circumstances to void an agreement than Pufendorf. Pufendorf’s first category is: “When in promising I have assumed something as a condition, without regard to which I would not have made the promise, there will naturally be no force in the promising.” Carmichael comments as follows:]

      This is to be allowed only in the following sense: If I have either expressly declared this assumption on my part as a condition of the promise, or if I thought in good faith that it was understood by the promisee from the nature of the transaction. For my own silent thoughts which I cannot reasonably believe will be understood by the party I am addressing, do not alter the sense of what I say, nor consequently its moral effect. [I.9.12.i]

      [Secondly, Pufendorf says: “If I have been impelled by error to make an agreement or a contract and I discover it when the matter is whole and nothing has yet been performed, it would be perfectly fair that the privilege of changing my mind be allowed to me.” Carmichael comments:]

       Yet this privilege cannot be claimed by perfect right, unless the error concerns something which the person who was in error at least thought was assumed as a condition on both sides. And in reciprocal agreements, an event which is not explicitly put as a condition is not easily understood to be such, unless it is either affirmed in the article itself actually to exist by the other party to the transaction, or it is such that without the condition which it is agreed the promisor cannot perform, it would be manifestly impossible or absurd to fulfill the promise, or finally unless it concerns the actual object