10 Judgment No. CCZ 2/18 Constitutional Application No. CCZ 86/15 The rationale for the prohibition of ex post facto criminal law is that criminal law requires proof of personal knowledge of the crime at the time the offence is alleged to have been committed. A person must bear personal responsibility for conduct he or she committed intentionally in the sense of knowing in advance that the conduct is proscribed by law as an offence. The law creating the offence must exist before the offence is committed. Section 70(1)(k) of the Constitution is an absolute prohibition of ex post facto penal laws. It applies only to retrospective criminal legislation. The legislative authority vested in the Legislature by the people in terms of s 117(2)(b) of the Constitution confers on it the power to make laws on any subject and at its discretion for the purposes of peace, order and good governance of Zimbabwe. Retrospectivity is one of the methods by which the Legislature chooses to implement civil legislation it enacts for the purposes of peace, order and good governance. The words “peace, order and good governance” are words of very wide import, giving wide discretion to the Legislature to pass laws for such purpose. The words have, of course, reference to the scope and not the merits of the legislation. See Att. Gen. for Saskatchewan v Canadian Pacific Rly. Co [1953] AC 594 at 613-614; Bribery Comr. v Ranasinghe [1965] AC 172 at 196-197; Cobbs & Co Ltd v Kropp [1967] AC 141 at 154 (PC). There is no constitutional provision that prohibits the Legislature from using retrospectivity as a method of giving effect to civil legislation. Retrospective lawmaking has been part of instruments of governance of human affairs for many centuries. The only constitutional limitation to the exercise of that power is that the retrospective application of the law must not infringe the fundamental human rights and freedoms enshrined in Chapter IV of the Constitution. Concerns about the inexpediency and injustice of the