delivered the opinion of the court.
The determination by this court of the various questions propounded in this case must affect in a large degree many private as well as public interests. We deem it proper, therefore, at the outset, to call attention to the construction already given to section 3, article 6, constitution, in relation to questions submitted by the executive and the general assembly. See opinion, per curiam, in 9 Colo. 620, concerning irrigation; also opinion by Chief Justice Helm, filed April 5, 1889, in response to a resolution requesting a construction of the provisions of senate bill No. 65, 12 Colo. .466. The latter opinion was announced after much consideration, and is authority for saying that this court must decide for itself, as to any given question, whether .or not it should exercise the jurisdiction of answering the same; and that only questions of law publici juris, and not questions affecting private or corporate rights, should be thus answered. That de*322cisión was based upon the fundamental doctrine that for this court to answer questions of the latter class, ex parte, would inevitably result in disposing of the rights or claims of litigants without due process of law, without counsel, and without allowing them their day in court. Having been thus guarded against expressing our views concerning the provisions of a pending bill which had not received, and might never receive, the legislative sanction, we should be doubly careful in discussing acts of the general assembly after they have received the approval of the executive.
The questions submitted in this case are of two kinds — ■ questions of fact and questions of law. It can hardly be expected that we should respond to the former. As to the questions of law presented, we shall endeavor to answer the same, so far as we can do so, by the announcement of general principles, without unduly prejudging private or corporate rights.
By section 16, article 10, of the constitution, appropriations and expenditures which may be made or authorized by the general assembly are of two general classes: First, ordinary, which include all kinds of appropriations and expenditures necessary and proper for the support of the government and its institutions in time of peace; second, extraordinary, or such as are necessary “ to suppress insurrection, defend the state, or assist in defending the United States in time of war.” In this opinion we have only to consider such as belong to the former or ordinary class. By said section 16, each and every general assembly is inhibited, in absolute and unqualified terms, from making appropriations or authorizing expenditures of the former class in excess of the total tax then provided by law, and applicable for such appropriation or expenditure, unless such general assembly shall provide for levying a sufficient tax, within constitutional limits, to pay the same within such fiscal year. This language needs no construction. It is plain, simple and *323unambiguous. It need not be misunderstood. It cannot be evaded. It means that the state cannot be plunged into debt by unauthorized legislation. If the general assembly pass acts making stich appropriátions or authorizing expenditures in excess of constitutional limits, such acts are void. They create no indebtedness against the state, and entail no obligation, legal or moral, upon the people, or upon any future general assembly. In the language of Mr. Justice Allen, of the New York court of appeals, cited below: “Neither the legislature nor the officers and agents of the state, nor all combined, can create a debt or incur an obligation for or in behalf of the state, except as to the amount and in the manner provided for in the constitution.” Cooley, Const. Lim. 69, 70; People v. May, 9 Colo. 85; Lake Co. v. Rollins, 9 Sup. Ct. Rep. 652; People v. Johnson, 6 Cal. 499; People v. Supervisors, 52 N. Y. 563.
We are asked what legal criterion is fixed by which it can be known, at the date of an act appropriating or authorizing the expenditure of money, whether such appropriation or expenditure will be in excess of the prescribed constitutional limits. We answer that there is no absolute criterion which can be relied upon in every instance and under all circumstances. The general assembly must, of necessity, exercise their own judgment in the first instance. But it must not be inferred from this, as some have supposed, that appropriations and expenditures which have been approved by the judgment of the general assembly as being within constitutional limits are therefore valid; for that would be to subordinate the positive requirements of the constitution to mere legislative control. It is absurd to say that a provision of the constitution, expressly designed to restrain and confine legislation within certain definite limits, is nevertheless subject to the unrestrained legislative will. Hence, while the general assembly must exercise their own judgment in the first instance, .yet if, by reason of *324error of judgment, or for any other cause, they exceed the constitutional limit in making appropriations or in authorizing expenditures, such excessive acts are mere nullities. People v. Supervisors, supra; Williams v. Louisiana, 103 U. S. 645; People v. May, 9 Colo. 412.
Though the general assembly must rely largely upon estimates in making appropriations, yet they are not without suitable guides for all practical purposes. They are clothed with ample powers for securing the most accurate and reliable information concerning the public revenue; and the sources of such information ai’e numerous and easy of access. The auditor’s estimates, contained in his biennial report to the governor, as required by section 1373, General Statutes, should be of great assistance; but they are not conclusive, and, if erroneous, afford no support to illegal appropriations. The appropriations for ordinary purposes generally extend through a period of only two fiscal years. The fiscal year commences on the 1st day of December (Gen. St. § 1403), one month prior to the beginning of the legislative session. The general assembly, composed of representatives from all parts of the state, aided by the records and reports of state and' county officers for preceding fiscal years, with power to take testimony and send for persons and papers, should be able to make such estimates that, with reasonable economy, all necessary expenditure may be provided for without transcending the constitutional limit. Illegal appropriations should be carefully avoided, inasmuch as they seriously damage, though they cannot wreck, the credit of the state; for, while they create no valid indebtedness, yet it cannot be denied that they tarnish the reputation of the government for business integrity and fair dealing, and are greatly injurious to the public welfare.
It has been suggested that the practice heretofore has been to make appropriations for the calendar instead of the fiscal year. This is not the method contemplated by *325the constitution, as is clearly manifest from several sections relating to the subject. Art. 10, §§ 2, 16. A more careful adherence to the constitutional method would undoubtedly prove advantageous, by making the line of demarkation between legitimate and excessive appropriations more easily discernible.
It will be observed that appropriations and expenditures for ordinary purposes are legitimate so long as they do not exceed the total tax already provided by law, and applicable for their payment, or which may, within constitutional limits, be so provided for their payment within the proper fiscal year. But it must not be overlooked that tax levies are seldom or never collected in full. Hence the appropriations and expenditures for each fiscal year must, if possible, be kept below the total amount of taxes levied for such fiscal year, so as to leave a margin equal to the loss which experience has shown will'occur on account of delinquent taxes; otherwise a deficit will occur in the treasury, and a constantly increasing indebtedness will inevitably result. It may be said that section 3, article 11, of the constitution was designed to provide for deficiencies of this kind., But’it will not do to depend upon the remedy therein provided. It is better to avoid a precipice than to take the risk of an injury by being too venturesome. Prevention is better than cure. At most, the relief which can be obtained under section 3 is very small, and can never exceed $100,000. Besides, it must not-be supposed that such remedy can be made available, except to provide for a valid indebtedness occasioned by “casual deficiencies of revenue. ” No appropriation or expenditure in excess of the constitutional limit, as above explained, can be thus provided for. A casual deficiency of the revenue is one that happens by chance or accident, and without design or intention to evade the constitutional inhibition. Hovey v. Foster (Ind.), 21 N. E. Rep. 41.
.What we have said of the legislative department in respect to making appropriations or authorizing expendí*326tures in excess of constitutional authority applies with equal force to the executive department in recognizing or dealing with legislation affecting the public revenue. If legislative acts making appropriations in excess of constitutional limits have unfortunately received the governor’s signature instead of his veto, he should nevertheless withhold his approval from any and all vouchers relating to such unconstitutional appropriations. So, also, the auditor should refuse to draw any warrant therefor, and the treasurer should decline to make payment thereon. In reference to matters arising under enactments clearly unconstitutional, the unauthorized act of one government official is no justification or excuse for a similar act by another. The character and scope of the interrogatories submitted compel us to speak thus plainly upon these points.
We have heretofore spoken of the ordinary appropriations and expenditures which may be made or authorized by the general assembly as including all such as are ‘ ‘ necessary and proper for the support of the government and its institutions in time of peace.” Chief among the necessary appropriations are such as are sufficient to defray the estimated expenses of the state government for each fiscal year.' This is the primary purpose for which an annual tax is required. It is made the imperative duty of the general assembly, by the express terms of the constitution, to provide by law for such a tax (art. 10, § 2), though the rate of taxation therefor must not exceed the limitation specified in section'll of the same article. Having provided a revenue for a specific purpose, in obedience tp the constitutional mandate, it is manifest that the fund cannot be diverted to other objects until the primary purpose of its creation is satisfied. It would be trifling with a serious provision of the constitution to hold that the obligation to provide a tax for a given purpose is imperative, but that the appropriation of the fund arising from such tax is optional.
Other provisions of the constitution are in harmony *327with this view. Referring to article 5, we find that section 32 provides for a general appropriation bill, which may embrace the ordinary expenses of the executive, legislative and judicial departments of the state, interest on the public debt, and for public schools, while all other appropriations must be made by separate bills, each embracing but one subject; section 21 restricts every bill, except general appropriation bills, to one subject, which shall be. clearly expressed in its title; and section 19 allows the general appropriation bill for the expenses of the government to be introduced at any time, though all other bills must be introduced during the first thirty days of the session. Section 12, article 4, is also spe-. daily applicable to general appropriation bills. The governor is thereby empowered to disapprove of any item or items contained in such, appropriations, and to approve the residue of the bill. This shows a clear’ purpose to invest the executive with discretion to save such appropriations as are necessary to defray the expenses of the government, without the danger of incumbering or defeating them by excessive or improvident expenditures.
Considering the great care thus taken to secure and guard such appropriations, w~e cannot doubt that the ordinary expenses of the legislative, executive and judicial departments of the state are the expenses primarily intended to be provided for by section 2, article 10. It would be a deplorable condition of affairs if, by making excessive appropriations, or by authorizing improvident expenditures, under enactments containing emergency clauses, the constitutional limit should be reached before the passage of appropriations indispensable for the support and maintenance of the several departments of the government, whereby the latter appropriations should be rendered unconstitutional.- We must not be understood as expressing any fear that the general assembly would intentionally attempt any such thing, though it might *328happen through inadvertence, if a different construction were given to the constitutional provisions under consideration.
In view of the examination we have given the subject, we are of the opinion that acts of the general assembly making the necessary appropriations to defray the expenses of the executive, legislative and judicial departments of the state government for each fiscal year, including interest on any valid public debt, are entitled to preference over all other appropriations from the general public revenue of the state, without reference to the date of their passage, and irrespective of emergency clauses. We do not mean, as has been claimed, that such appropriations are valid, if they exceed the limit prescribed by section 16, article 10; nor have we considered what item or items would be entitled to the preference in case such appropriations in the aggregate should be in excess of such constitutional limit. Such a question is not presented in the case before us, and we trust such a contingency may never occur.
The public school fund of the state is inviolate. It is protected from all invasion by sundry constitutional safeguards, and therefore is not included within the purview of this opinion.
Appropriations other than those necessary to defray the expenses of the state government, and to pay the interest on the public debt, as above explained, and being such as are proper to foster and maintain public institutions and public improvements, may be made by the general assembly to the extent of the surplus over and above the amount required for the necessary appropriations aforesaid: provided, always, that the aggregate of such appropriations, when added to the necessary appropriations aforesaid, do not exceed the limits prescribed b3r section 16, article 10, constitution. In case such appropriations- overrun the constitutional limit, the question of preference between conflicting claimants would *329almost necessarily involve important private and corporate rights, and therefore should not be decided in an opinion like this, even though some considerations publici juris may also be involved, but should be left for adjudication in the ordinary course of judicial proceedings.
We do not deem it proper-to further extend this opinion. In answering the interrogatories submitted, so far as we have felt at liberty to go, we have endeavored to be specific and guarded in our language, — specific, so as not to be misunderstood; , guarded, lest, being unaided by the vigilance of opposing counsel, some provision of the constitution or law might be overlooked, and erroneous conclusions reached.
The thanks of the court are due to Honorable S. W. Jones, attorney-general; H. Riddell, Esq., of Breckenridge; and John Dewitt Reitz, Esq., of Colorado Springs, for the presentation of valuable briefs amici curies, in response to our invitation.