The aim of this diploma thesis is to analyze selected ways of
deciding the subject-matter in international commercial
arbitration. The thesis is divided into four chapters. The
first chapter provides a brief theoretical introduction into
the topic and explains the essential terms. The second chapter
deals with the institute of amiable compositeur and ex aequo at
bono and the third chapter explores lex mercatoria. In these
chapters the aforementioned institutes are characterized, their
historical development is provided, based on examples from
specific countries and institutions the possibilities of their
regulation are illustrated, with help of arbitration awards
their use in practice is clarified and the importance of these
institutes is evaluated. The fourth chapter describes marginal
ways of deciding the subject-matter: decision-making based on
general legal principles, trade usage, deciding using the
method tronc commun, deciding based on Muslim shari’a and
eventually, decision-making based on the existence of contracts
enabled by the concept of self-regulatory contracts. The thesis
tends to confirm or refute these hypotheses - the ways chosen
are clearly theoretically defined and limited; these ways are
despite their origins and use dependant on national law and
they cannot exist without it.