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Peter Mazzacano

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CISG; international commercial law; law merchant; lex mercatoria


This paper will consider the medieval lex mercatoria (Law Merchant) as a set of autonomous commercial customs, which initially materialized in the form of trade usages and practices, but were ultimately codified in national laws and international conventions, such as the UN Convention on Contracts for the International Sale of Goods (CISG). The paper will focus on the historical development of the lex mercatoria, and will attempt to highlight how the conventional academic debates surrounding have become irrelevant. The thrust of this paper will argue that the lex mercatoria is simultaneously both non-state law and state-based law. It is not created in the state, it is not created exclusively in commerce. Rather, it's created by the law itself. To borrow a term from biology, the lex mercatoria is autopoietic. By "autopoietic" I suggest the lex mercatoria is a type of autonomous organism. It's a self-contained and self-maintaining legal order. But it's not so much a body of substantive law, but rather a process whereby it organizes and produces itself. Paradoxically, in this way it's both autonomous and non-autonomous law.