Non-performance and fault: from the Spanish Civil Code to modern Contract Law. Special reference to contracts for the supply of services

Abstract

This article aims to contrast the relevance of «fault» in our legal system regarding non-performance of contracts with the neutral notion of non-performance in modern contract law. In particular, the article analyzes the Spanish Supreme Court’s doctrine on non-performance and the right to damages, in cases of contracts for the supply of services. The main focus of  the article is to try and identify the different criteria the Supreme Court uses to determine non-performance of «the duty of best efforts» (based on debtor’s fault), and contrasts this with the non-performance of «the duty to achieve a specific result» (based on failure to achieve the result). The final goal of the article is to show how these two different approaches to non-performance can be harmonized with the unitary and neutral concept of non-performance settled in the Vienna Convention of International Sales of Goods, the UNIDROIT Principles, the Principles of European Contract Law, and the Spanish Proposal for Modernization of the Spanish Civil Code.