One of the fundamental principles of contract law (pacta sunt servanda or untouchable contract law) is that agreements concluded seriously must be applied, but that agreements which clearly harm the interests of the Community as a whole, whether they are contrary to law or morality (contra bonos mores) or if they are contrary to social or economic expediency. is not forced. These contracts are illegal for reasons of public order. The law considers that illegal or illegal contracts are either and therefore unenforceable, or valid, but unenforceable. 10 In the event of an agreement to sell certain goods and the goods subsequently pass through through no fault of the seller or buyer before the danger is transferred to the buyer, the contract is avoided. R.S., at 408, p. 10. Similarly, evidence may be added to the evidence of the additional oral part if there are not two ancillary agreements, but an interconnected contract, part of which is written and the rest oral, provided that it is clear that the parties do not intend the written part to be the exclusive monument of the entire agreement. In such a case, called “partial integration,” the integration rule simply prevents the authorization of extrinstatic evidence to contradict or vary the written part of the agreement. The court may hear evidence of the circumstances, including negotiations by the parties, to determine whether, by written agreement, they intend to integrate their entire transaction or only partial integration.