Causa and Its Importance in Contractual Law Disputes

The author presents causa as a central institution in contract law. The starting point is the need to distinguish between the legal rule requiring a valid legal transaction to have an existing and licit cause on one hand and the concept of causa in contract law on the other hand. Codifying the former does not resolve two central questions: first, what is causa, and second, what is its meaning and scope in contract law? These are conceptual issues. The author seeks answers to these questions by examining the nature of things, the broad concept of causa, which complements the three abstract contractual types of causa, and by situating causa within both the narrower and broader context of the institutions of the Slovenian Obligations Code. The article demonstrates the importance of causa in both phases of a contract (stipulation and fulfilment), as well as in the retrospective, interpretative phase. It also uses case law examples to show how causa encompasses concepts such as manifest disproportion, the common purpose of the contracting parties, the purpose of the contract, and the expectations of the parties. These concepts are linked to numerous abstract factual situations in contract law. The most evident examples are the institutions of clausula rebus sic stantibus, the rule of simultaneous performance, and the legal qualification and interpretation of contracts. In complex court cases in contract law, causa is therefore a central guide for judges, functioning similarly to general principles.

Keywords: causa, basis, grounds, contract, common purpose of the contracting parties, rebus sic stantibus, principle of equivalence of reciprocal performances, interpretation of the contract.