Non-binding legal instruments are generally considered non-binding agreements, but they offer great potential for transformation into «binding law» in the future. This «hardening» of soft law can occur in two different ways. One of them is when declarations, recommendations, etc. are the first step towards a contract-making process that refers to the principles already contained in non-binding legal instruments. Another possibility is that non-contractual agreements are supposed to have a direct impact on State practice, and to the extent that they are successful, they can lead to the creation of the common law. Soft law is a practical option for negotiations that might otherwise stagnate if legally binding commitments were sought at a time when, for political and/or economic reasons, it is not convenient for negotiating parties to make important commitments at any given time, but still want to negotiate something in good faith in the meantime. The generic term soft law encompasses a variety of instruments of different types and functions that make it very difficult to formulate it into a single formula. Its only common characteristic is that it is in written form, but the other characteristics are variable and negotiable and they form an «infinite variety». Thus, the term includes non-binding rules contained in treaties, non-binding or voluntary resolutions, recommendations, codes of conduct and standards. A good definition of soft law is difficult to find, as the term has been the subject of heated debate among those who deny the existence of such a right and those who regard it as a new quasi-source of international law, and those who study the concept often require authors to take a position or another.

In short, it can be defined as «prescriptive provisions contained in non-binding texts» (Shelton 2000, p. 292; cited under General Overviews). It also covers weak provisions in international agreements that do not entail obligations. Soft law emerged at a time when positivist theories were forced to deal with the regulation of new legal issues that were part of the Domain reserve. Since then, the Academy has revisited the sources of international law, considering soft law as a source that challenges the canonical foundation of international law, thus breaking the ideal of hard legalization and introducing varying degrees of normative intensity. Soft law has given rise to doctrinal debates on the difference between soft law and hard law, based on positions taken on the basis of the foundations or sources of international law or the legislative process. Some authors rely on a binary distinction between legal and non-legal rules, while others choose the idea of graduated normativity or continuum or the existence of a penumbra in which soft law has its essence. Non-binding legal instruments can even be adopted by new actors involved in informal international law processes with varying degrees of authority, such as the world`s new unrecognized legislators. Soft law also has various functions that include the emergence of law and the interpretation and adaptation of hard law, and it is reflected in the delegation of delegated functions to international bodies responsible for the development of international law. Softness has even found its way into legal institutions and international organizations, endowing them with soft responsibilities and flexible instruments of monitoring and enforcement. Given these comments, and despite its criticisms, soft law is here to stay.

An oft-cited seminal work that criticizes the notion of «relative normativity» and warns against blurring the distinction between normative and non-normative rules and the distinction between normative and prenormative actions in the international standard-setting process. A must for researchers and students approaching the subject. Available online for purchase or subscription. A French version is available: «Vers une normativité relative en droit international?» Revue générale de droit international public 86 (1982): 5–47. The term soft law is used to refer to agreements, principles and declarations that are not legally binding. Non-binding legal instruments are mainly found at the international level. UN General Assembly resolutions are an example of non-binding law. Binding law generally refers to legal obligations that are binding on the parties involved and that can be enforced in court. D`Aspremont and Aalberts initiate the debate on soft law that Ellis and Goldman passionately develop with different and convergent theoretical approaches to soft law. Ellis sums up the spirit of the symposium by stating that the role of soft law is to «provoke inquiries and debates about the nature, sources, validity and legitimacy of law» (p. 372).

Baxter 1980 and Weil 1983 are seminal works that approach soft law from opposing positions. Baxter 1980 sees in soft law the infinite variety of international law, which expresses a «variable intensity of agreement» (p. 566). Weil 1983 is the author`s most cited seminal work, in which he criticizes the notion of «relative normativity» and warns against blurring the distinction between normative and non-normative rules and the distinction between normative and prenormative actions in the international standard-setting process. Klabbers 1996 has consistently opposed the notion of soft law, arguing that it is redundant because «the traditional binary conception of law is quite capable of fulfilling the functions normally attributed to soft law» (p. 168). Chinkin 1989 takes a far-sighted position that evaluates the advantages and disadvantages of soft law, taking into account its impact on legislative procedures as well as on the implementation and jurisprudence of international law. Shelton 2000 is a groundbreaking document from the American Society of International Law that evaluates soft law standards and discusses compliance with soft law through an assessment of various non-binding instruments on key issues. Abbott and Snidal 2000 overcome disciplinary divisions and criticisms of soft law to argue that «the field of soft law begins as soon as legal agreements on one or more of the dimensions of commitment, precision and delegation are weakened.» .