Hall's statement, widely quoted by writers on State succession, has retained a good deal of its validity. From Grotius to O'Connell, a long series of distinguished publicists have attempted to throw light upon the doctrinal obscurity of the problem. Many of them have displayed remarkable juristic imagination, but have also shown a regrettable lack of precision and discipline. In their justification, however, it must be conceded that the abundant judicial and diplomatic practice on State succession has always been—and still is—contradictory and obscure.