Causa of the contract: prolegomena to the choice of a legal model during the recodification of the civil legislation of Ukraine

The article is devoted to clarifying the meaning of causa as a legal basis of a contract. It is emphasized that the current legislation of Ukraine does not contain the concept of causa, but judicial practice, in particular, regarding disputes on the recognition of transactions as invalid, operates with a concept close to causa - «legal and factual purpose, which should not be obviously unlawful and unfair, and which agreements concluded by participants in civil legal relations should have». The origin of causa in Roman law is traced. The author draws attention to a fragment of the Roman lawyer Ariston (Ulp. 4 ad ed. D.2.14.7.2), in which the presence of causa determines the recognition of a contractual obligation, even if it does not correspond to a known contractual type. In this sense, causa is considered to be a contractual function, a legally relevant goal that determines the requirement for the implementation of a counter-grant. In this respect, causa should be understood as the intention to exchange benefits, which justifies the recognition and legal protection of unnamed contracts. A review of legislation on the application of causa is made. Examples where the legislation directly indicates the need for the existence of causa of the contract are the civil codes of Italy and Spain. Causa is considered to be an essential element of the contract in these codes and must comply with imperative norms, public order and good customs. In the doctrine, two main approaches for understanding causa can be distinguished: the abstract and the objective causa, which concerns the existence of the contract, and the subjective and the concrete causa, which concerns legality. The first approach is based on the economic and social theory of causa, according to which causa is a function of social interest, in which private autonomy is manifested. The second approach perceives causa as a specific category, that is, an individual function of the contract, an interest, on the implementation of which the actions of the parties are directed. Adhering to the second approach, the author concludes that it is necessary to include causa in the essential terms of the contract at the legislative level.