Good faith in the lex mercatoria
: an analysis of arbitral practice and major Western legal systems

  • Lorena Carvajal-Arenas

Student thesis: Doctoral Thesis


his thesis is a comprehensive guide to the current interpretation of the principle of good faith in the lex mercatoria. It sets out the full background to this
interpretation, exploring the development of good faith in major legal cultures in the Western world and in arbitral practice.

Modern lex mercatoria is one of the most conspicuous manifestations of globalization in the field of law. Previous examples of global law are the Roman ius gentium and the medieval law merchant. The principle of good faith has been fundamental in all these manifestations. The thrust of this thesis represents an investigation of the reasons for the essential role of good faith in universal contexts, and in particular, its meaning in the lex mercatoria.

It is argued here that national laws have been influential on the meaning of good faith in the current lex mercatoria. Hence, four major legal systems in the civil and the common law areas are studied: German, French, US and English. Nonetheless, other national systems are also mentioned throughout the thesis. This analysis will reveal the fundamental dynamism of the concept of good faith.

This thesis challenges the traditional view of good faith as a moral and subjective concept, impractical and difficult to assess. It will show that an objective notion of good faith is vigorous in international commerce nowadays.

This thesis explains that good faith in the lex mercatoria is interpreted as cooperation of the parties to a commercial contract. This notion fits the experience of
global trade today. This theory will be verified through an analysis of: comparative legal history, sociological, philosophical and political theories, international instruments embracing the lex mercatoria and also through cases from national courts and international arbitration.

This comprehensive study will serve as a context for future investigations on ancillary duties that emanate from good faith and on the principle of good faith in specific stages of the contractual iter, such as re-negotiation of the agreement. It will contribute to the harmonization and unification of law in different regions of the world and also to global projects containing the language of good faith. Likewise, it will be useful for traders and practitioners, especially arbitrators dealing with good faith in international disputes between merchants.
Date of AwardDec 2011
Original languageEnglish
Awarding Institution
  • University of Portsmouth
SupervisorMunir Maniruzzaman (Supervisor)

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