A new penalty for non-compliance with obligations: price reduction

Article 1223 of the Civil Code provides: “ The creditor may, after formal notice, accept an imperfect non-performance of the contract and request a proportional reduction in the price.
If he has not yet paid, the creditor notifies his decision to reduce the price as soon as possible ”.

A first analysis, conceptual, highlights a strong break of our law with its original spirit, since article 1223 adds, with regard to the treatment of non-performance, to the reparation of the harmful consequences resulting therefrom, a possible reduction of the price, the two penalties may moreover be cumulative.
This could be a revolution in our law since until now, in the absence of demonstration of harmful consequences attached to the commission of a fault in the performance of obligations and therefore the allocation of damages, one party could not call into question the financial balance of the contract, except in a few rare matters.
However, article 1223 of the Civil Code now enshrines this possibility by allowing a party, claiming a breach of contract, to request a price reduction, and correlatively, the judge who would be seized of the application of the said article to make that -this.
It being specified that the concept of price must obviously be considered as representing the financial counterpart of an obligation, which has the consequence that it is a sanction which could be implemented in any type of contract comprising such a counterpart.
A more pragmatic examination leads to questions about the concrete implementation of this mechanism, which is supposed to allow a simplified resolution of the difficulty that non-performance would pose.
First of all, it appears that the price reduction would be invoked in cases qualified as imperfect non-performance.
It follows that such a mechanism can certainly be implemented without great difficulty in respect of obligations whose non-compliance is easily measurable, such as those relating to easily quantifiable goods or services or those assuming performance within a certain period of time. time.
But how will the imperfection of the non-performance be assessed when the notion of quality is at stake or, if the notion of obligation of means still has a meaning, the implementation of these by the debtor of the 'obligation ?
The question then arises as to how the correlation will operate between the imperfect nature of the non-performance and the price reduction likely to result.
Although the idea of ​​proportionality is very opportunely put forward, it could in practice prove to be quite insufficient to enable the amount of the price reduction to be easily determined. Proportionality evokes the idea of ​​a mathematical rule that could perfectly apply to execution and price.
This is certainly a myth, however, or an intellectually simplistic approach. Price is indeed a complex concept and the law does not cover its various components, only some of which are likely to be related to the non-performance in question.
However, very logically, the proportionality put forward should only apply to them. It is to be feared that in practice, neither the parties, nor the judge, nor even the expert appointed to give a technical opinion, will really be able to apply this proportionality and that the implementation of this provision will succeed. to a very bad and random intrusion into the economic balance of the contract.
If there is one certainty, it is that the drafter of the contract must today take the measure of this new form of sanction and, if necessary, taking into account the apparently supplementary nature of article 1223 of the Civil Code , apprehend the advisability of excluding or adjusting its application contractually.