The article explores different ways of understanding the autonomy of the will in Private International Law. It looks at how this autonomy can be seen as coming from freedom of contract, a unique type of legal transaction, a method for regulating international private law, or a result of law interacting with public relations. By critiquing these approaches, the author suggests that the autonomy of the will can be divided into two stages: first, as a rule allowing parties to choose the applicable law in certain cases, and second, as a quasi-law determined directly by the parties' agreement.