Point I. On the Qualities of Consent

Consent must be internal, fully deliberated, external and intimated to the other party, and indeed by the contracting party or in his name, and finally simultaneous. It is said:

I. Internal. If it is not internal, consent or volition is lacking in reality. Therefore a fictitious contract is invalid, that is, one entered into externally but without the mind of contracting (St. Alphonsus, III, 709; VI, 832). One who by contracting fictitiously has inflicted damage on the other party is bound to repair it, even, if it cannot otherwise be repaired, by now truly contracting (St. Alphonsus, III, 709; VI, 832, 833).

Corollary I. One who wills to contract as others are accustomed to do truly contracts, even if he merely does not know that an obligation arises, because he implicitly wills the obligation. The same seems to have to be said of him who wills to contract as others are accustomed to do, although he judges that an obligation does not arise, because by willing the contract he also seems implicitly to will the obligation, which he does not explicitly exclude.

Corollary II. One who wills to contract, but has the mind of not obliging himself, seems not to contract, because he excludes that without which a contract cannot exist; hence those two volitions destroy each other. Indeed even the other volition, as more particular, seems to prevail over the former (St. Alphonsus, III, 201).

Corollary III. One who wills to contract validly contracts, even if he has the mind of not fulfilling the obligation; for the said volitions, as regarding diverse and separable objects, do not exclude each other.

II. Fully deliberated; for only an act of this kind can beget obligation and the acquisition of a right.

III. External; namely insofar as it must be intimated to the other party.

IV. Intimated to the other party, as follows:

1. The consent of the one offering the contract must be intimated to the other party. For the offerer cannot be bound with respect to the other party unless he has offered to the other party that by which he binds himself, that is, his own consent. But consent is offered to the other party through intimation.

2. The consent of the one accepting the contract must be intimated to the other party, as will be explained:

a) If there is question of an onerous contract, the answer is affirmative. For the acceptor, equally as the offerer, cannot be bound with respect to the other party unless he himself has offered to the other party that by which he binds himself, that is, his own consent; but consent is offered through intimation.

b) If there is question of a gratuitous contract, the answer is negative, because in the case the acceptor, with respect to the other party, is not bound or burdened by any obligation, so that the reason set forth above does not hold in the case.

Corollary. The offerer and the acceptor of a contract, for example of buying-selling, per se can revoke consent - for example consent given by letters - by a telegraphic message, as long as the consent has not yet become known to the counterparty. I said per se; for law, custom, or the manifest will of the offerer can bring it about that the offerer can no longer revoke consent without injury after it has become known to the counterparty; for example, if someone offers and transmits to another a sum of money for buying a thing, he sufficiently indicates that he renounces the right of revoking consent.

V. Intimated to the other party by the contracting party or in his name; namely insofar as it must be intimated. The reason is that only the author of the consent can offer to the other party that by which he binds himself, that is, consent.

VI. Simultaneous with the other, because otherwise they do not truly come together into one. Nevertheless it suffices that one consents while the consent of the other endures.