Statement by Mr. Justice GRAY:
This was action, brought March 10, 1886, by the state of California against the San Pablo & Tulare Railroad Company, a corporation of California, in the superior court of the city and county of San Francisco, ( and thence removed by the defendant into the circuit court of the United States, upon the ground that it was a suit arising under the constitution and laws of the United States,) to recover taxes assessed by the state board of equalization, under sections 4 and 10 of article 13 of the constitution of California, (which are copied in the margin,1) as state and county taxes for the year July 1, [149 U.S. 308, 309] 1885-June 30, 1886, upon the defendant's franchise, roadway, roadbed, rails, and rolling stock in the counties of Alameda, Contra Costa, and San Joaquin.
The defendant, in its answer, filed March 19, 1886, and averring the facts necessary to present the question, set up the following defense: 'The provision of section 4 of article 13 of the constitution of the state of California, providing for the assessment of the property of railroad and other quasi public corporations, is in contravention of the provisions of the fourteenth amend ment of the constitution of the United States, in that it discriminates against such corporations, in this: That whereas, under said section 4 of said article 13 of the constitution of the state of California, if the property of natural persons, or corporations not quasi public, has a mortgage, lien, or incumbrance thereon, they are not liable to assessment or taxation upon such property, but only upon the value of their interest in such property over and above the value of such mortgage lien or incumbrance, whereas, in the case of the property of railroad and other quasi public corporations, no such allowance or deduction is made, had, or allowed with respect to any mortgage, lien, or incumbrance there may be upon such property; and also in this: that while section 10 of article 13 of the constitution of the state of California provides the same mode for the assessment of the franchises, roadway, roadbed, rails, and rolling stock of all railroads operated in more than one county, whether such property be owned by [149 U.S. 308, 310] railroad or other quasi public corporations or by private corporations or by natural persons, yet section 4 of article 13 of said constitution permits or allows indebtedness secured by mortgage, trust deed, or otherwise, to be deducted from the value of such property only when it is owned by natural persons or corporations not quasi public, and denies such deduction when the property is owned by railroad or other quasi public corporations.'
On July 14, 1886, the attorneys for the parties filed in this and three similar cases the following stipulation in writing:
On July 15, 1886, the circuit court gave judgment for the defendant in the present case.
In the case of California v. Central Pac. R. Co., referred to in that stipulation, this court did not decide the question now presented, but on April 30, 1888, reversed the [149 U.S. 308, 311] judgment of the circuit court on other grounds. 127 U.S. 1, 45 , 8 S. Sup. Ct. Rep. 1073.
On March 6, 1889, the parties, by another stipulation in writing, agreed that the previous judgment of the circuit court in the present case be set aside, and the case submitted to the circuit court upon an agreed statement of facts, 'on which findings shall be made and conclusions of law drawn by the court.'
On September 6, 1889, the circuit court, pursuant to this stipulation, ordered its former judgment to be set aside, and made and filed findings of fact in accordance with the agreed statement.
By these findings of facts it appeared that, before and at the time of the assessment of these taxes, the defendant owed a debt secured by mortgage of its railroad, its franchise, and its rolling stock and appurtenances, to the amount of more than $3,000 a mile; that the state board of equalization valued and assessed the defendant's franchise, roadway, roadbed, rails, and rolling stock, not separately, but together, ( and not including any other kind of property,) at their full value, without deducting the value of the mortgage or any part thereof, although knowing of its existence, and did not deem or treat the mortgage as an interest in the property, and assessed the whole value of the property to the defendant as if there had been no mortgage thereon, but made the assessment upon the same basis for valuation as all other property in the state was valued for the purpose of taxation; and that there were at that time divers railroads in the state owned and operated by corporations other than railroad corporations, and by individuals and partnerships.
Upon the facts found, the circuit court concluded, as matter of law, that the defendant was entitled to judgment. Judgment was entered accordingly, and the state of California sued out this writ of error.
The attorney general of the state admitted in his brief, and, when this case was called for argument, stated in open court, the following fact:
W. H. H. Hart, Atty. Gen. Cal., for the People. [149 U.S. 308, 313] Harvey S. Brown, for defendant in error.
Mr. Justice GRAY, after stating the facts in the foregoing language, delivered the opinion of the court.
Upon the fact most properly and frankly admitted in open court by the attorney general of the state of California, there can be no doubt that this writ of error must be dismissed, because the cause of action has ceased to exist. Any obligation of the defendant to pay to the state the sums sued for in this case, together with interest, penalties, and costs, has been [149 U.S. 308, 314] extinguished by the offer to pay all these sums, and the deposit of the money in a bank, which by a statute of the state have the same effect as actual payment and receipt of the money; and the state has obtained everything that is could recover in this case by a judgment of this court in its favor. The duty of this court, as of every judicial tribunal, is limited to determining rights of persons or of property which are actually controverted in the particular case before it. When, it determining such rights, it becomes necessary to give an opinion upon a question of law, that opinion may have weight as a precedent for future decisions. But the court is not empowered to decide moot questions or abstract propositions, or to declare, for the government of future cases, principles or rules of law which cannot affect the result as to the thing in issue in the case before it. No stipulation of parties or counsel, whether in the case before the court or in any other case, can enlarge the power, or affect the duty, of the court in this regard.
The case at bar cannot be distinguished in principle from previous cases in which writs of error have been dismissed by this court under similar or analogous circumstances. Lord v. Veazie, 8 How. 251, 255; Cleveland v. Chamberlain, 1 Black, 419; Paper Co. v. Heft, 8 Wall. 333; San Mateo Co. v. Southern Pac. R. Co., 116 U.S. 138 , 6 Sup. Ct. Rep. 317; Little v. Bowers, 134 U.S. 547 , 10 Sup. Ct. Rep. 620; Manufacturing Co. v. Wright, 141 U.S. 696 , 12 Sup. Ct. Rep. 103. See, Elgin v. Marshall, 106 U.S. 578 , 1 Sup. Ct. Rep. 484.
Writ of error dismissed.
[ Footnote 1 ] Sec. 4. A mortgage, deed of trust, contract, or other obligation, by which a debt is secured, shall, for the purposes of assessment and taxation, be deemed and treated as an interest in the property affected thereby. Except as to railroad and other quasi public corporations, in case of debts so secured, the value of the property affected by such mortgage, deed of trust, contract, or obligation, less the value of such security, shall be assessed and taxed to the owner of the property; and the value of such security shall be assessed and taxed to the owner thereof in the county, city, or district in which the property affected thereby is situate. The taxes so levied shall be a lien upon the porperty and security, and may be paid by either party to such security; if paid by the owner of the security, the tax so levied upon the property affected thereby shall become a part of the debt so secured; if the owner of the property shall pay the tax so levied on such security, it shall constitute a payment thereon, and to the extent of such payment a full discharge thereof: provided, that if any such security or indebtedness shall be paid by any such debtor or debtors, after assessment and before the tax levy, the amount of such levy may likewise be retained by such debtor or debtors, and shall be computed according to the tax levy for the preceding year.
Sec. 10. All property, except as hereinafter in this section provided, shall be assessed in the county, city, city and county, town, township, or district in which it is situated, in the manner prescribed by law. The franchise, roadway, roadbed, rails, and rolling stock of all railroads operated in more than one county in this state shall be assessed by the state board of equalization at their actual value; and the same shall be apportioned to the counties, cities and counties, cities, towns, townships, and districts in which such railroads are located, in proportion to the number of miles of railway laid in such counties, cities and counties, cities, towns, townships, and districts.