I. Error

I. Division. Error is distinguished:

1. Into substantial and accidental. Substantial error is had: 1° when the nature of the contract intended by one party is different from the nature of the contract which the other party intends, as if you accept something as a gift, when the other party intends to lend it for use; 2° when the object of consent, at least morally speaking, is different from the object of the present contract, that is, the object upon which the expression of consent is borne, as if you intend to buy a gem, and the expression of consent is borne upon glass; 3° error concerning the person with whom one contracts can be substantial only then when, as in matrimony, the person constitutes the object of the contract.

Others, however, speak thus with respect to error concerning the person: error concerning the person can be substantial or accidental. In matrimony it is always substantial, because the person itself is the object about which the contract is made. In other contracts error is substantial if the person is intended per se and principally, as commonly happens in gratuitous contracts; for example, if you give alms to Peter, thinking him to be poor, when he is rich. Error is accidental if the person is something secondary, which most often has place in onerous contracts, for example if you buy something from Paul the heretic, thinking him to be Catholic; sometimes it also has place in gratuitous contracts, as if you give alms to Peter the poor man, thinking him to be Paul.

Outside the cases enumerated above, error is accidental.

2. Into error which gave cause to the contract, and such as did not give cause to it, according as the contract, with the error set aside, would not have been entered into, or nevertheless would have been entered into.

II. Influence upon the contract. Error concerning the nature of the contract, as is clear, makes the contract void. Hence now let us speak about error which concerns the object of the contract. Now then:

1. Substantial error makes the contract void. For it brings it about that consent is borne upon an object different from the object of the present contract, that is, from the object upon which the expression of consent is borne. Therefore consent is lacking with respect to the object of this contract (St. Alphonsus, III, 714; cf. can. 104).

2. Accidental error effects these things:

a) It makes the contract void if the contracting party attaches his consent to the accident in such a way that it falls back into a condition sine qua non (cf. can. 104). Otherwise it does not make the contract void, because it does not prevent consent from being borne upon the object of the present contract. But the case of nullification occurs especially in error concerning the person, and indeed, that we may apply what others according to the things said in n. 836 hold as substantial error, if the person is intended per se and principally, as commonly happens in gratuitous contracts; for example, if you give alms to Peter, thinking him to be poor, when he is rich. Otherwise it must be said if the person is something secondary, which most often has place in onerous contracts, for example if you buy something from Paul the heretic, thinking him to be Catholic; sometimes also in gratuitous contracts, as if you give alms to Peter the poor man, erroneously thinking him to be a religious (St. Alphonsus, III, 737).

b) It renders the contract rescindable if the error was induced by fraud, and indeed by the other contracting party, and gave cause to the contract. Otherwise it does not render the contract even rescindable.

The reason for the former is that a contract induced by the fraud of the other contracting party involves an injury inflicted by the other contracting party; and this injury must be repaired by him. It is repaired by the fact that the contract involving the injury is removed, in other words rescinded. Therefore it must be rescinded, or at least rescission of it must be offered, by him who inflicted the injury; corresponding to this obligation is the right of rescinding in him who has suffered the injury. If the contract has already been given to execution, the injury is repaired by the fact that the deceived person is restored to his former state with respect to his things (St. Alphonsus, III, 715).

The latter involves three things, namely:

a) Accidental error does not render the contract rescindable if it was not induced by fraud, but, for example, inculpably or fortuitously, or by a non-free cause; because an injury, at least a formal one, to be repaired is lacking.

b) Accidental error does not render the contract rescindable if it was induced by the fraud of a third party. The reason is that injury to be repaired by the other contracting party, for example by Peter, is absent. But an injury inflicted by a third party, Paul, upon one contracting party, James, is not a reason why the other contracting party, Peter, can be deprived, by rescission of the contract, of the right acquired through the contract with James.

c) Accidental error does not render the contract rescindable if it did not give cause to the contract. For from the fact that, with the error excluded, the contract nevertheless would have been entered into, it follows that the contract, equally as other contracts entered into without error, was acceptable to the will; hence, equally as those other contracts, it must be held as firm and non-rescindable.

Nevertheless, observe that if the due equality between wage and price has been injured because of error, it must be repaired; and if fraud has been added, the deceiver is bound to repair also other damages, if perhaps they have followed from the fraud (St. Alphonsus, III, 714 and 715).

Note 1. With respect to ecclesiastical matter, observe these words of can. 104: "In contracts error can give place to a rescissory action according to the norm of law"; likewise these words of can. 1684, § 1: "If someone ... circumvented by fraud ... has entered into a contract which is not null by the law itself, he can, ... once the fraud has been proved, obtain ... the rescission of the contract by the action which is called rescissory."

Note 2. What civil law establishes concerning error, see in the law of one's country.