delivered the opinion of the court:
The ultimate -question is whether the declaration by the general assembly that the act is necessary for the immediate preservation of the public peace, health or safety, is conclusive that it is a statute which excepts it from the referendum. In re Senate Resolution, 54 Colo. 262, 130 Pac. 333, in response to questions propounded by the senate, we said with respect to the constitutional provision, which recites that the power reserved, designated the referendum, “may be ordered except as to laws necessary for the immediate preservation of the public peace, health or safety;” that, “Whether a law is of this character, is for the general assembly to determine, and when it so determines, by a declaration to that effect in the body of a proposed act, we are of- the opinion that such declaration is conclusive upon all departments of *7government, and all parties, in so far as it abridges tbe right'to invoke the referendum.” It is now'- urged that this question was not involved, not raised by the questions propounded, nor argued in the briefs and not germane to the particular points under consideration. When the situation which confronted the senate is understood, as appears from the statement preceding the opinion, it is clear that the question we determined, which is now urged is dictum, was involved.
At the fifteenth session of the general assembly, in obedience to a constitutional amendment adopted at the general election of 1902, an act was passed providing foían eight-hour day for persons employed in mines underground, and in specified ore reduction works. Laws 1905, 284. " At the eighteeiith session of the general assembly an act was passed, Laws 1911, 454, of a similar nature, which in express terms repealed the act passed in 1905. The act of 1911 was approved June 2, of that year. It did not contain any declaration to the* effect that it was necessary for the immediate preservation of the public peace, health or safety. August 3, 1911, and within ninety days after the eighteenth general assembly adjourned for the session, there was filed with the Secretary of State, a petition purporting to be signed by the requisite number of legal voters, asking that the 1911 act be referred to the-people for approval or rejection at the ensuing general election. On July 2, 1912, there was filed with the Secretary of State a petition purporting to be signed by the necessary per centum of the legal voters of the'state, requesting that there be submitted at the next general election, for adoption or rejection, a proposed eight hour law, which in some respects, at least, was in conflict with the act of 1911. This initiated law purported to expressly repeal the acts of 1.905 and 1911. Both measures were published by the Secretary of State, and, at the general election in November, 1912, were adopted. *8When the questions were submitted by the senate the general assembly had under consideration a proposed eight hour law, the purpose of which was to take the place of the referred and initiated acts. It thus appears, as stated in the opinion, that the senate was confronted with an anomalous situation, because two acts were upon the statute books, covering the same subject, in conflict with each other; one purporting to repeal the other, and that from the questions propounded, though not directly expressed, it was the desire of the senate to pass an eight hour act which could not be suspended under the referendum, provided it had authority to do so in such manner as would prevent the situation then presented from being repeated in the future. It was, therefore, apparent that in order to enable the general assembly to pass an eight hour law relating to the employment of men engaged in working in mines which could be made effective and not suspended in its operation by invoking the referendum, it was necessary.to advise the senate in response to its questions, how this desirable result could be accomplished, and hence, the contention that what was said with respect to the power of the general assembly to declare that a law was necessary for the immediate preservation of the public peace, health or safety, and that such declaration was conclusive upon all departments of government, in so far as it abridged the right to invoke the referendum, was not dictum, but was directly involved and germane to the questions propounded by the senate.
Since answering these questions, the general assembly has been guided in passing laws by what was there stated. Our opinion was given in obedience to the Constitution, which requires the Supreme Court to give its opinion upon important questions, upon solemn occasions, when required by the Senate or House of Representatives. Certainty of the law is always desirable, and *9when a decision is rendered, it should not he changed unless it is clearly wrong.
Counsel for petitioner now contend that the declaration in 54th Colorado, whether a law is of the character which excepts it from the referendum, is for the legislature to determine, is wrong. Their premise is that it is a judicial function to scrutinize an act, the general assembly has declared “necessary for the immediate preservation of the public peace, health or safety, ’ ’ and determine whether it is of that character, and whether a law is exempt from the referendum depends not upon the declaration of the general assembly, but whether such declaration is true as a matter of fact. The vital question, therefore, presented for our consideration is, what tribunal is vested with authority to determine whether a law is of the character which excepts it from the referendum. In other words, does this authority rest with the general assembly, or with the judicial department. This inquiry is much simplified by bearing in mind that the exception in the constitutional amendment, with respect to the referendum, is not confined to such laws as the general assembly may legally enact under the police powers of the state. The language of the amendment is broader and includes all laws necessary for the immediate preservation of the public peace, health or safety. Their exception from the operation of the referendum does not depend alone upon their character, but upon the necessity for their enactment, and being put in force in order to accomplish the purposes specified. Except as limited by the Federal or State Constitutions, the authority of the General Assembly is plenary. This has so often been declared that citation of authority to support it is unnecessary. The judicial department, however, cannot exercise any authority or power except that granted by the Constitution. Field v. People, 2 Scam. (Ill.) 79. By the constitutional provision under consideration, it is *10provided that the power of the referendum “may bo.ordered except as to laws necessary for the immediate preservation of the public peace, health or safety.” . The object of this was -to prevent the delay incident to laws enacted for such purposes not taking effect until ninety days after the final adjournment of the general assembly passing them, or their suspension until the next general election by invoking the referendum. This was necessary for the protection of the people of the state, as the suspension of such laws, even for a brief' period might be disastrous and wisely the people did not reserve .the power to approve or disapprove such laws, so that as to them the authority of the general assembly, which it may»exercise under the Constitution, is not affected:
By article III of our Constitution it is provided:
“The powers of the government of this state are divided into three distinct departments, — the legislature, executive and judicial; and no person or collection of persons charged with the exercise of powers properly belonging to one of these departments shall exercise any power properly belonging to either of the others, except as in this constitution expressly directed or permitted.”
During the process of the enactment of a law the legislature is required to pass upon all questions of necessity and expediency connected therewith. The existence of such necessity is a question of fact, which the general assembly in the exercise of its legislative functions must determine; and under the constitutional provision, above quoted, that fact cannot be reviewed, called in question, nor be determined by the courts. It is a question of which the legislature alone is the judge, and when it determines the fact to exist, its action is final. The courts cannot be advised what facts the general assembly acted upon when it determined that a statute was necessary for the purposes specified, and to undertake to review its action upon a question of fact, would be a *11collateral attack upon its judgment. The general assembly has full power to pass laws for the purposes with respect to which the referéndum cannot be ordered, and when it decides by declaring in the body of an act that it is necessary for the immediate preservation of the public peace, health or safety, it exercises a constitutional power exclusively vested in it, and hence, such declaration is conclusive upon the courts in so far as it abridges the right to invoke the referendum. Kadderly v. Portland, 44 Ore. 118, 74 Pac. 710; Oklahoma City v. Shields, 22 Okl. 265, 100 Pac. 559; State v. Moore, 76 Ark. 197, 88 S. W. 881, 70 L. R. A. 673 ; State v. Levan, 14 S. D. 394, 85 N. W. 605. To conclude the contrary would violate the constitutional provision to which we have referred, the plain object of which is to inhibit one department of government exercising any power that by the Constitution is vested in another. The Constitution defines the powers and duties of each department, and should the courts .venture to substitute their judgment for that of the legislature in any case where the Constitution has vested the legislature with power over the subject, they would enter upon a field where it is impossible to set limits to their authority, and where their discretion alone would measure the extent of their interference. Cooley’s Constitutional Limitations, 7th ed. 236.
The argument of counsel for petitioner that the courts are vested with authority to determine whether an act is of the character which excepts it from the referendum, notwithstanding the declarations by the general assembly that it is, is based upon the assumption that unless the courts exercise the power to determine that question, the people can be deprived of the right to refer a law, if the legislature, either intentionally or through mistake, declares falsely or erroneously that a law is necessary for the. immediate preservation of the public peace, health or safety. The answer to this proposition is, that *12under the Constitution the general assembly is vested with exclusive power to determine that question, and its decision can no more be questioned or reviewed than the decisions of this court in a case over which it has jurisdiction. It will not be presumed that the general assembly will disregard its duty or fail to observe the mandates of the Constitution, or not act honestly. Neither can it be assumed that the courts are better able to determine whether a law is immediately necessary for the preservation of the public peace, health or safety, than the legislature. Power may be abused, but that is not a valid reason for one co-ordinate branch of the government to assign for limiting the power „and authority of another department. The judicial department is as much bound by constitutional provisions as any other. “It cannot run a race of opinions upon points of right reason and expediency with the law-making power.” The courts do not make constitutions or change them. They can only construe the provisions of that instrument. So that the only power we can exercise in solving the question presented, is to ascertain where the authority to determine, when a law is exempt from the referendum, is lodged. The cases cited by counsel for petitioner from Washington and California, holding that the question of whether a law is necessary for the purposes specified is subject to review by the courts, appear to be grounded upon the assumption that the constitutional provisions, with respect to the initiative and referendum, should be construed so as to make effective the power of the referendum. State v. Meath, 84 Wash. 302, 147 Pac. 11; McClure v. Nye, 22 Cal. App. 248, 133 Pac. 1145. In the Washington case, and also in a Michigan case, cited by counsel, (Attorney General v. Lindsay, 178 Mich. 524, 145 N. W. 98), it is held that the authority of the legislature to make the declaration that an act is necessary for the immediate preservation of the public peace, health *13or safety, is confined, to such laws as the legislature may legally enact under the police power of the state. Neither of these reasons furnish the test by which to ascertain whether the courts have authority to determine if a law is of the character which exempts it from.the referendum, or inquire whether the declaration of the legislature that it is, is false or erroneous.
The only test is, what department of government is authorized, under the Constitution, to determine whether an act is necessary for the purposes specified. This authority, as we have pointed out, is vested in the general assembly, and if that body erroneously or wrongfully exercises that authority, the remedy is with the people. It is not subject to review by the courts or any other authority, except the people. Under the reserved power of the initiative and referendum, after the declaration by the General Assembly that a law is necessary for the immediate preservation of the public peace, health or safety, when not referred to the people for their judgment, it still remains with them if they are dissatisfied with it, to cause a measure to be submitted at the next general election for its repeal. If, from experience, it appears necessary to deprive the general assembly of the power to declare a law necessary for purposes specified, the people have the power to initiate an amendment to the Constitution which will take from the general assembly the authority which they have vested in it. But this cannot be accomplished by the courts usurping a power they do not possess.
The decision In re Senate Resolution, was rendered at the January Term, 1913. In that opinion it was said that the declaration by the General Assembly that a measure was necessary for the immediate preservation of the public peace, health or safety, prevented it from being referred by invoking the referendum. The people, if dissatisfied with the power they have conferred upon *14the legislature to thus abridge the right of the referendum, could have submitted an amendment to the Constitution at the general election of 1914, to deprive the General Assembly of this power. They did iiot do so, and while their failure to submit such an amendment is uot conclusive, it is, at least, persuasive that they do not wish to take from the general assembly that authority.
The judgment of the District Court is affirmed.
Judgment affirmed.
Decision en bane.