If it were written some fifty years ago, a work like the present one, seeking to explain the essentials of American constitutional law to a British audience, would hardly have included a chapter devoted to administrative law. The British jurist could not be expected to show an interest in developments abroad in a field whose existence he had been accustomed to deny at home. If, however, a half-century ago it required the 'prophetic sense of a Maitland'1to realize the great growth of administrative law, today awareness of that growth has become a commonplace. Administrative law, as a leading American judge has recently affirmed, is now recognized as 'the outstanding legal development of the twentieth century, reflecting in the law the hegemony of the executive arm of the government'.2 Nor, it should be noted, is the realization of this confined to members of the legal profession. Indeed, as significant to the student of administrative law as the tremendous extension of his subject, has been the widespread public interest displayed in it in recent years.
Public concern over trends in this field reflects an increasing awareness of its importance in dealing with the many problems arising out of the expansion of the role of the State. Human existence is inconceivable outside of society.3 At the same time organized society threatens to overwhelm the individual. 'There is not a moment of his existence where modern man does not find himself in contact with government and its agents.'4 In the contemporary State, government tends more and more to become the all-dominant factor in society, by taking over or controlling the functions hitherto performed by private institutions. As it does so it comes into ever-increasing contact with the individual life. 'It is in this ceaseless contact of the individual with the State that the danger of arbitrariness has especially arisen.'5
The dangers arising out of the expansion of State power were well put a generation ago by Lord Macmillan's Committee on Finance and Industry: 'The most distinctive indication of the change of outlook of the 5____________________