Special Majority

The makers of the Constitution wanted it to be both 'flexible' (open to change) and 'rigid' (resistant to casual change) at the same time, so that it could be corrected where it had genuine faults, without being so easy to change that any ruling party could rewrite it to suit itself.

Many articles of the Constitution can be amended by a simple law of Parliament — the wording of such articles typically says Parliament 'may by law' do something (for example, Article 2 lets Parliament admit new states into the Union 'by law', and Article 3 lets it alter the area of a State 'by law'). These are the flexible parts of the Constitution: there is no difference at all between passing an ordinary law and amending these provisions.

For the remaining, more sensitive parts of the Constitution, Article 368 lays down a stricter procedure — special majority. Ordinarily, a bill needs only the support of a simple majority of members present and voting. An amendment bill needs two things at once: (i) support of a majority of the total membership of that House (not merely of those present that day), and (ii) support of at least two-thirds of the members who are actually present and voting. Both Houses of Parliament must pass the bill separately in this manner — there is no joint sitting for a constitutional amendment. Once passed, the bill goes to the President for assent, but — unlike an ordinary bill — the President has no power to send an amendment bill back for reconsideration. …