Gajendragadkar, C. J., speaking for six learned Judges of this Court said (at p. 446) (of SCR) = (at pp. 762-763 of AIR) : "In a democratic country governed by a written Constitution, it is the constitution which is supreme and sovereign. It is no doubt true that the Constitution itself can be amended by the Parliament, but that is possible because Art. 368 of the Constitution itself makes a provision in that behalf, and the amendment of the constitution can be validly made only by following the procedure prescribed by the said article. That shows that even when the Parliament purports to amend the Constitution, it has to comply with the relevant mandate of the constitution itself. Legislators, Ministers, and Judges all take oath of allegiance to the Constitution, for it is by the relevant provisions of the Constitution that they derive their authority and jurisdiction and it is to the provisions of the Constitution that they owe allegiance. Therefore, there can be no doubt that the sovereignty which can be claimed by the Parliament in England, cannot be claimed by any Legislature in India in the literal absolute sense." 572. The principle of the supremacy of the Constitution was then declared by the majority of the learned Judges of this Court in Kesvananda's case (AIR 1973 SC 1461) (supra) to be a part of the basic structure of the Constitution. The minority opinion, while not specifically dissenting from this view, was that even what was considered by the majority to be a part of "basic structure" was alterable under article 368. But, no judge of this Court has so far held that, without even attempting to change what may be the basic structure of constitution itself, by appropriate amendments, judicial power could be exercised by Parliament under Article 368 on the assumption that it was already there. 573. M. C. Setalvad, a distinguished jurist of India, said (See: "The Common Law of India" Hamlyn Lectures-12th series — 1960) (at p. 174-175) : "The Constitution divides the functions of the Union into the three categories of executive, legislative and judicial functions following the pattern of the British North America Act and the Commonwealth of Australia Act. Though this division of functions is not based on the doctrine of seperation of powers as in the United States yet there is a broad division of functions between the appropriate authorities so that, for example, the legislature will not be entitled to arrogate to itself the judicial function of adjudication. "The Indian Constitution has not indeed recognised the doctrine of separation of powers in its absolute rigidity but the functions of the different parts or branches of the Government have been sufficiently differentiated and consequently it can very well be said that our Constitution does not contemplate assumption, by one organ or part of the State, of functions that essentially belong to another'. (See: Rai Saheb R. J. Kapur v. State of Punjab, (1955) 2 SCR 225 at p. 235 = (AIR 1955 SC 549) at p. 555-56). This will no doubt strike one accustomed to the established supremacy of Parliament in England as unusual. In the course of its historical development Parliament has performed and in a way still performs judicial functions. Indeed the expression 'Court of Parliament" is not unfamiliar to English lawyers.