The term "constitution" is usually applied to an attempt to embody in a single authoritative document, or a small group of documents, the fundamental political institutions of a state. But such an attempt is rarely, if ever, completely successful; and even if the constitution when framed covers all the main principles on which the government is based, it often happens that they become modified in practice, or that other principles arise, so that the constitution no longer corresponds fully with the actual government of the country. In France, for example, the principle that the cabinet can stay in office only so long as it retains the confidence of the popular chamber, the principle, in short, of a ministry responsible in the parliamentary sense, was not mentioned in the charters of 1814 or 1830, and yet it was certainly firmly established in the reign of Louis Philippe; and it is noteworthy that this same principle, on which the whole political system of the English self-governing colonies is based, appears neither in the British North American Act nor in the Australian Federation Act. The first of those statutes, following the English tradition, speaks of the Privy Council for Canada,[1:2] but never of the cabinet or the ministers; while the Australian Act, going a step farther, refers to the Queen's Ministers of State,[1:3] but ignores their responsibility to the parliament.[2:1] Again, in the United States, the provision that the electoral college shall choose the President has become so modified in practice that the electors must vote for the candidate nominated by the party to which they owe their own election. In choosing the President they have become, by the force of custom, as much a mere piece of mechanism as the Crown in England when giving its assent to acts passed by the two Houses of Parliament. Their freedom of choice is as obsolete as the royal veto. So far, therefore, as this meaning of the term is concerned, the constitution of England differs from those of other countries rather in degree than in kind. It differs in the fact that the documents, being many statutes, are very numerous, and the part played by custom is unusually large. [Sidenote: Not Changeable by Ordinary Legislation.] [Sidenote: Rigid and Flexible Constitutions.]