The historical endeavour, extending from the First Hague Conference of 1899 until eventual success in 1920, to establish a permanent international court as distinct from ad hoc tribunals, was inspired by the belief that only a court established on a permanent basis could, besides deciding disputes, make an adequate contribution to the progressive development of international law as a working system of law. This belief implied a commitment to the acceptance of a case-law system as the way forward. This acceptance was confirmed by the decision to publish law reports for the Permanent Court of International Justice; for, given law reports, a system based upon case law invariably follows.

The principal features of this case law were economically and inimitably described and analysed by Hersch Lauterpacht in his Development; it is therefore a happy circumstance that this new and considerable study by Judge Shahabuddeen was one of the series of Hersch Lauterpacht Memorial Lectures given in Cambridge University.

The formal basis of this case law is still that now laid down in the present Article 38 of the Statute of the International Court of Justice (for earlier drafts see p. 52 below) which lists amongst what the Court is to apply, ‘subject to the provisions of Article 59, judicial decisions and the teachings of the most highly qualified publicists of the various nations, as subsidiary means for the determination of rules of law’.