concurring.
Mr. Justice Reed, Mr. Justice Murphy, Mr. Justice Burton and I concur in the result. We are of the opinion that the tax here involved should be sustained and the judgment below affirmed.
In view of our decisions in South Carolina v. United States, 199 U. S. 437; Ohio v. Helvering, 292 U. S. 360; Helvering v. Powers, 293 U. S. 214; and Allen v. Regents, 304 U. S. 439, we would find it difficult not to sustain the tax in this case, even though we regard as untenable the distinction between “governmental” and “proprietary” interests on which those cases rest to some extent. But we are not prepared to say that the national government may constitutionally lay a non-discriminatory tax on every class of property and activities of States and individuals alike.
Concededly a federal tax discriminating against a State would be an unconstitutional exertion of power over a coexisting sovereignty within the same framework of government. But our difficulty with the formula, now first suggested as offering a new solution for an old problem, *587is that a federal tax which is not discriminatory as to the subject matter may nevertheless so affect the State, merely because it is a State that is being taxed, as to interfere unduly with the State’s performance of its sovereign functions of government. The counterpart of such undue interference has been recognized since Marshall’s day as the implied immunity of each of the dual sovereignties of our constitutional system from taxation by the other. McCulloch v. Maryland, 4 Wheat. 316. We add nothing to this formula by saying, in a new form of words, that a tax which Congress applies generally to the property and activities of private citizens may not be in some instances constitutionally extended to the States, merely because the States are included among those who pay taxes on a like subject of taxation.
If the phrase “non-discriminatory tax” is to be taken in its long accepted meaning as referring to a tax laid on a like subject matter, without regard to the personality of the taxpayer, whether a State, a corporation or a private individual, it is plain that there may be non-discriminatory taxes which, when laid on a State, would nevertheless impair the sovereign status of the State quite as much as a like tax imposed by a State on property or activities of the national government. Mayo v. United States, 319 U. S. 441, 447-448. This is not because the tax can be regarded as discriminatory but because a sovereign government is the taxpayer, and the tax, even though non-discriminatory, may be regarded as infringing its sovereignty.
A State may, like a private individual, own real property and receive income. But in view of our former decisions we could hardly say that a general non-discriminatory real estate tax (apportioned), or an income tax laid upon citizens and States alike could be constitutionally applied to the State’s capitol, its State-house, its public school houses, public parks, or its revenues from taxes or *588school lands, even though all real property and all income of the citizen is taxed. If it be said that private citizens do not own State-houses or public school buildings or receive tax revenues, it may equally be said that private citizens do not conduct a State-owned liquor business or derive revenue from a State-owned athletic field. Obviously Congress, in taxing property or income generally, is not taxing a State “as a State” because the State happens to own real estate or receive income. Whether a State or an individual is taxed, in each instance the taxable occasion is the same. The tax reaches the State because of the Congressional purpose to lay the tax on the subject matter chosen, regardless of who pays it. To say that the tax fails because the State happens to be the taxpayer is only to say that the State, to some extent undefined, is constitutionally immune from federal taxation. Only when and because the subject of taxation is State property or a State activity must we consider whether such a non-discriminatory tax unduly interferes with the performance of the State's functions of government. If it does, then the fact that the tax is non-discriminatory does not save it. If we are to treat as invalid, because discriminatory, a tax on “State activities and State-owned property that partake of uniqueness from the point of view of intergovernmental relations,” it is plain that the invalidity is due wholly to the fact that it is a State which is being taxed so as unduly to infringe, in some manner, the performance of its functions as a government which the Constitution recognizes as sovereign. '
' It is enough for present purposes that the immunity of the State from federal taxation would, in this case, accomplish a withdrawal from the taxing power of the nation a subject of taxation of a nature, which has been traditionally within that power from the beginning. Its exercise now, by a non-discriminatory tax, does not curtail the business of the state government more than it does the *589like business of the citizen. It gives merely an accustomed and reasonable scope to the federal taxing power. Such a withdrawal from a non-discriminatory federal tax, and one which does not bear on the State any differently than on the citizen, is itself an impairment of the taxing-power of the national government, and the activity taxed is such that its taxation does not unduly impair the State’s functions of government. The nature of the tax immunity requires that it be so construed as to allow to each government reasonable scope for its taxing power, Metcalf & Eddy v. Mitchell, 269 U. S. 514, 524. The national taxing power would be unduly curtailed if the State, by extending its activities, could withdraw from it subjects of taxation traditionally within it. Helvering v. Powers, supra, 225; Ohio v. Helvering, supra; South Carolina v. United States, supra, and see Murray v. Wilson Distilling Co., 213 U. S. 151, 173, explaining South Carolina v. United States, supra.
The problem is not one to be solved by a formula, but we may look to the structure of the Constitution as our guide to decision. “In a broad sense, the taxing power of either government, even when exercised in a manner admittedly necessary and proper, unavoidably has some effect upon the other. The burden of federal taxation necessarily sets an economic limit to the practical operation of the taxing power of the states, and vice versa. Taxation by either the state or the federal government affects in some measure the cost of operation of the other.
“But neither government may destroy the other nor curtail in any substantial manner the exercise of its powers. Hence the limitation upon the taxing power of each, so far as it affects the other, must receive a practical construction which permits both to function with the minimum of interference each with the other; and that limitation cannot be so varied or extended as seriously to impair *590either the taxing power of the government imposing the tax ... or the appropriate exercise of the functions of the government affected by it.” Metcalf & Eddy v. Mitchell, supra, 523-524.
Since all taxes must be laid by general, that is, workable, rules, the effect of the immunity on the national taxing power is to be determined not quantitatively but by its operation and tendency in withdrawing taxable property or activities from the reach of federal taxation. Not the extent to which a particular State engages in the activity, but the nature and extent of the activity by whomsoever performed is the relevant consideration.
Regarded in this light we cannot say that the Constitution either requires immunity of the State’s mineral water business from federal taxation, or denies to the federal government power to lay the tax.