The constitution has also been modified by decisions of the courts. The courts cannot change a single word in the constitution; they merely interpret its meaning. Their function is =jus dicere, non dare= (to interpret the law, not to make it), as the saying goes. But the fact remains that changes in the meaning of words are equivalent for all practical purposes to changes in the words themselves. The Supreme Court, in a long series of decisions, has greatly expanded the powers of the national government by the interpretation of words and clauses in the written constitution. It has decided that the power to borrow money includes the power to establish banks, that the power to regulate commerce includes the power to fix railroad rates, that the power to establish post-offices includes the power to punish those who use the mails for a fraudulent purpose, and so on. It has been the function of the court to make the words spell out new meanings to fit new situations. One cannot today obtain an adequate knowledge of what these words and phrases mean by merely reading the document; it is necessary to go through the decisions of the Supreme Court and find out just how this great tribunal has interpreted them. [Sidenote: 3. Statutes.] The constitution has been developed by law. Many things were left in general terms in order that the details might be settled by Congress or by the state legislature. Nothing is said in the constitution about the organization or procedure of the federal courts. All this has been built up by laws. Nor is anything said about the method of nominating congressmen, or the form of the ballot, or the duties of election officials. That, too, is arranged by law. Much of what we call the machinery of American government today rests upon ordinary laws which can be changed by Congress or the state legislatures at any time. [Sidenote: 4. Amendments.] Finally, the constitution can be changed, and on nineteen matters has been changed by amending it. The constitution provides four possible methods of making and ratifying amendments,—two of initiating and two of ratifying. These various ways are stated in the document (Article V) more briefly and more clearly than they can be recapitulated here. But every one of the amendments thus far made has been proposed and adopted in one and the same way, namely, proposal by Congress and ratification by three-fourths of the state legislatures. [Sidenote: Method of making amendments.] The other plan of proposing amendments, that is by calling a constitutional convention, would open the gates for a general revision or for the submission of an entirely new constitution, which is something that public opinion has not yet seemed to favor. If, however, Congress should at any time endeavor to thwart the will of the people by declining to propose an amendment strongly demanded by public opinion its hand could be forced by resort to the convention method. [Sidenote: Nature of the nineteen amendments.]