In addition, written agreements should understand that one of the fundamental principles of contract law (pacta sunt servanda or treaty untouchability) is that contracts concluded with seriousness should be applied, but whether they are agreements that are clearly detrimental to the interests of the Community as a whole, whether they are contrary to existence or morality (contra bonos mores) or contrary to social or economic utility. , is not forced. These contracts are illegal for public policy reasons. The law considers illegal or illegal contracts either to be non-acute and therefore unenforceable, or to be valid but unenforceable. The problem of the occupants was that an oral agreement on the sale of real estate could not be valid, as it is one of the few types of agreements that our law requires, a) in writing and (b) by both the seller and the buyer «or by their agents acting on their written power». This is a mundane law that is dealt with in Section 2 of the alienation of the country 68 of 1981. Another problem is not what has been said, but what has not been said. By nature, the fine oral chords are rather thin. It is often only when the parties are in the middle of the contract, when the cracks begin to appear.
Forgetting important details can make the treaty fail. However, it is recommended to avoid oral agreements, as it is not possible to prove the terms of the agreement in the event of a dispute. On the other hand, contract law in the Netherlands is based on laws on guns and nature. When she took the canonist position, it was said that all treaties were an exchange of promises that were consensual and bonae fidei, that is, simply based on mutual consent and good faith. From the point of view of Christians, that it is a sin to break the promise, the church`s lawyers have developed the principle of pacta sunt servanda, according to which all serious agreements must be applied, that strict formalities, as prescribed by secular law, have been respected.  According to the theory of the cause, in order to be binding, the treaty had to have an iusta causa or a legitimate ground that corresponded to Christian moral imperatives and which derives not only from a legitimate or just right, title or motive, but also from love and affection, moral consideration or past services.  A nudum pactum has been redefined as any agreement that, for lack of cause, is not applicable.