In the laws of both Iran and France, the fundamental elements required for the formation of contracts and the sanction for their absence have been discussed. The overlooked sections have also been supplemented by legal scholars and jurisprudence. Nevertheless, the necessity or lack thereof for the existence of the conditions and elements that form contracts throughout their duration has neither been explicitly and comprehensively addressed nor independently discussed in the laws of the two countries. Consequently, the issue has not been examined as thoroughly as it deserves by legal scholars and jurisprudence, and many aspects remain vague and ambiguous within the judicial systems of both countries. Nonetheless, a general rule has emerged in this area as a principle: after a contract is validly concluded, logically, the absence of necessary elements for its formation does not lead to its lapse, just as the death or the lack of capacity of a person or a retraction of intent and consent does not affect the fate of the juridical act. However, it seems unlikely that this rule has no exceptions. Among the questionable cases is the impact of personality or characteristic decline on contracts whose contracting party's personality was the primary reason for the concluding the contract.
The debate over the significance of personality in the formation and durability of personal contracts—referred to as "intuitus personae"—is a controversial issue in personal contracts. A crucial question here is the impact of the breach of the intended personality of the contracting parties at the time of the contract's conclusion and its disappearance during its execution. In other words, if the personality of one party or specific characteristics and abilities were central to the intent and will of the contracting parties at the time of the contract's conclusion, and later turns out that the intended individual lacked them or that a mistake occurred regarding the intended personality, what would be the implications? Likewise, on the ground of the centrality of the person's identity or capabilities, what would happen to the contract if the person dies or those characteristics are declined during the contract's execution?
The term " intuitus personae," which signifies the strengthening of personal bonds in obligations, is a concept among the general contractual rules that practically has been overlooked by the civil laws of Iran and France, and a few regulations can be found to refer to it. The only explicit legislation in this area in both countries refers to the nullity of a contract in the case of a mistake regarding the other party's personality, provided that the importance of personality is such that it was the primary cause of the contract; Article 201 of the Iranian Civil Code and Article 1134 of the French Civil Code address this issue under the topic of mistakes.
In France, significant initiatives have been undertaken by legal scholars to clarify the juridical act described as " intuitus personae " from the ambiguity surrounding it. What is agreed upon in French doctrine is that the contract lapses when the abilities and characteristics of the contracting party are central and it is proven that those abilities and characteristics are declined.   Yet, there is no doctrinal or judicial consensus on describing the legal situation created by the decline of a person's identity or personal abilities: terms like "dissolution," "retroactive termination", "non-retroactivity termination", "canceled", " and "lapse" are all used to describe the extinction of juridical act in personal obligations in French law. This is equally true in Iranian law, where terms such as "dissolution," "disappearance," and " canceled " have been mentioned in similar contexts.
Therefore, considering the importance of personality in these types of contracts on one hand, and the silence of the legislator regarding their disappearance on the other in both understudied countries, the main objective of this study is to examine the fate of contracts when the condition regarding personality at the moment of contract formation is lost or it declines during the life of the contract in both French and Iranian law. Accordingly, we seek to find answers to several main questions: first, what are those personal contracts, and in what cases might contracts be disrupted due to the lack of a central personality or disruption thereof? Second, what is the proposed solution regarding the decline of personality in personal contracts under French law, and can this solution be extrapolated to Iranian law? Additionally, the practical effects of the sanction and its impact on analyzing the outcomes of the discussed contracts is another important question we aim to address.
As a presumption, it seems that personal contracts vary between objective and subjective ones, with some being inherent to certain contracts while others stem from the desires and wills of the contracting parties.
Moreover, in French law, the concept of "caducité"—which has recently been incorporated into recent modifications in the civil code—has received considerable attention in describing the fate of juridical acts in contracts and obligations formed with consideration of the person or their abilities. According to Article 1186 of the new French Civil Code: " A contract which has been validly formed lapses if one of its essential elements disappears." Thus, from the perspective of many legal scholars, whenever the identity of the parties or the capabilities of the executor becomes a part of the contract and acts as a determining element of consent or the subject of the obligation, it will face the consequence of caducité. The same approach, although it had precedents in the jurisprudence of France before the adoption of the new Civil Code, has been strengthened by the new law and is now the prevailing approach in current jurisprudence in that country.
 This theory seems extendable to Iranian law, both because it has rational and legal supports in Iranian law and because other conceivable sanctions share similar issues with the French legal system, as well as due to the positive practical effects of the theory.
Therefore, it is suggested that the Iranian legislator, in the section on general contract rules, while recognizing the sanction of the caducité of contracts as one of the effects of breaching the essential elements of the validity of contracts, and as the absence of the essential elements of the contract at the moment of its formation leads to the contract's nullity, affirm the fundamental nature of personality and personal aspects in personal contracts, and explicitly state that the disappearance of the essential elements of the contract during execution also leads to its lapse.