K.A. Usacheva

Why is the contract binding? This question might be simple, bui it hasn`t been answered clearly for last several of millennia. The distance between the types of given explanations continues to increase, it is reflected not only in the basis of the notion “contract”, but on the construction of the matter of contract law as well. This gives rise to various modifications of the “theory of flexible systems” that are gaining popularity in the field of contract law and attempting to connect and to balance the existing approaches. The other side of the modern discussions about the concept of the contract concern the disputes about the criteria for distinguishing the contract that giving rise to legal relations from the other agreements which don’t have such nature. Identifying complementarities to separate the contracts from non-binding agreements also helps to give a clearer view of the legal concept and the core of the contract. This article discusses both sets of questions supported by Russian and foreign legal tradition, evaluates the numerous variations of the “theory of flexible systems” as deducting the “what ought to be” from the “what is”, considers the interaction of the subjective, objective and formal in the contract as the combination of factors indicating the formation of the legal relation between the parties