The Republic of South Africa is a constitutional state founded, inter alia, on the values of supremacy of the constitution and of the rule of law. In the context of political governance, the supreme Constitution is now the ultimate source of all lawful authority in the country. In the last several years, the superior courts have insisted that the exercise of public power should not only be legally authorised, but also that it must, in addition, conform to certain, minimun standards of justice. This "new" approach was underlined by the Late Chief Justice, Mahomed in these ringing Words:- No President, however formidable be his reputation or scholarship, and no official, however efficient or well-menaing can make any Law or perform any act which is not sanctioned by the Constitution. In this paper, we discuss this controlling power of the courts with specific reference to selected cases implicating the presidency and demanding that the conduct of the President should pass constitutional muster, in line with this immortal adage: "No man is above the law and no man is below it, nor do we ask any man's permission when we require him to obey it. -- Obedience to the law is demanded as a right, not asked as favour." At the heart of this paper is this eternal question: In a modern, democratic state like the Republic of South Africa, how can the machinery of government, in general and the vast powers in the Presidency, be so operated as to leave the maximum personal liberty to the individual citizen? A review of some landmark cases will reveal that while the courts respect the doctrine of separation of powers, they do not shy away from their "traditional" role as sentinels or bulwarks of indivual freedom by insisting, for example, that those who exercise state power, including the President, are constrained by the principle that they may exercise only those powers and perform only those functions which are conferred upon them by the Law; that decisions should be rationally related to the purpose for which the power was given or should not be arbitrary and that holders of public power should act in good faith and not misconstrue the amplitude of their powers. It is hoped that this paper will make a modest contribution to the theme of this very important conference, namely "that the laws of the land lay the foundation of peace and order, and ensure that people progress in all aspects of their lives - whether in business, education, travel, health or recreation. The role of public officials is to create, scrutinize, implement and uphold the laws in order to protect the rights of every individual, corporate entity or institution." [ABSTRACT FROM AUTHOR]