7 The principle of legality [6] I have already outlined the importance of this case from the perspective of the right of all people, but in particular women and children, who are the most vulnerable and the most affected, to be protected against sexual violence. But that alone cannot be decisive of this appeal. The reason is that the decision by the high court flows from a constitutional principle that is equally fundamental, namely the principle of legality.8 The power of the state to prosecute people and the power of courts to try, convict and sentence offenders are public powers of the greatest importance. In the history of the struggle for basic human rights the abuse of the criminal process by governments to suppress dissent and stifle the views of those opposed to the regime in power is notorious. One can trace this in the history of many countries, but our own experience suffices to underline the fact that abuse of power, including abuse of the criminal process, lies at the heart of tyranny and oppression. In the light of that history our Constitution demands that the ‘Legislature and Executive in every sphere are constrained by the principle that they may exercise no power and perform no function beyond that conferred upon them by law’.9 The courts, as the guardians of the Constitution, are likewise constrained. Accordingly, it is essential to ensure that the powerful feelings of disgust that sexual assault and sexual abuse arouse do not overwhelm the need for the State, in the form of the prosecuting authority in this case, to satisfy us that it would be lawful for a court trying Mr Prins, not only to convict him, but also to sentence him in a lawful manner. Just as we cannot invent new punishments, 10 so also we cannot invent a power to impose a punishment if none exists. 8 Fedsure Life Assurance Ltd v Greater Johannesburg Metropolitan Council 1999 (1) SA 374 (CC) paras 56 to 59. 9 Fedsure para 58. 10 S v Malgas 2001 (2) SA 1222 (SCA) para 2.