demonstrably justifiable in a free and democratic society, it cannot be saved pursuant to section 1 of the Charter. The determination of s. 1 validity follows the Oakes test first expressed in R v Oakes, which follows four parts, of which the last three have been named as the "proportionality test": the reason for the rights violation must be "pressing and substantial" there must be a "rational connection" between the rights-infringing measure and the objective the measure must be the least restrictive means for realizing the objective the deleterious effects of the measure must be proportionate to the importance of the objective Although modified in subsequent jurisprudence to relax its strictness, Oakes continues to be of valid application. However, the provincial education power under Section 93 of the Constitution Act, 1867 is plenary, and is not subject to Charter attack, so long as it does not extend beyond the confines of Section 93's mandate to fund Roman Catholic separate schools and public schools. Legislative competence In order to rationalize how far each jurisdiction may use its authority, certain doctrines have been devised by the courts: There are also differences in legislative competence in each of the Provinces, as each had entered Confederation on somewhat different terms. As Viscount Simon of the Privy Council noted in 1953: Pith and substance The pith and substance doctrine is founded on the recognition that it is in practice impossible for a legislature to exercise its jurisdiction over a matter effectively without incidentally affecting matters within the jurisdiction of another level of government. Also, some matters are by their very nature impossible to categorize under a single head of power: they may have both provincial and federal aspects. The double aspect doctrine, which applies in the course of a pith and substance analysis, ensures that the policies of the elected legislators of both levels of government are respected, by recognizing that both Parliament and the provincial legislatures can adopt valid legislation on a single subject depending on the perspective from which the legislation is considered (i.e., depending on the various aspects of the matter in question). In certain circumstances, however, the powers of one level of government must be protected against intrusions, even incidental ones, by the other level. For this purpose, the courts have developed the doctrines of interjurisdictional immunity and federal paramountcy. The Parliament of Canada has power to bind Her Majesty both