The QPC breaks with the long-standing French tradition of légicentrisme (i.e. the sacred, hence intangible character of the laws being the expression of Rousseau’s general will) and fosters the common view that the Constitution is actually at the apex of the legal system. (…) With this new procedure, which significantly enhanced the rule of law in France, arose the issue of the ratione temporis application of the Conseil constitutionnel’s decisions. Should statutes still have some effects after they have been declared unconstitutional and repealed? And what about their past effects prior to the decision or to the abrogation?
(Temporal Effects of Judicial Decisions in France în The Effect of Judicial Decisions in Time, Intersentia, 2014, la p. 112)