Opinion of the Court. charter which created it is a contract whose obligations neither party can repudiate without the consent of the other. All that is within the scope of this contract need not be determined. Obviously, one obligation assumed by the corporation was to construct and operate a railroad between the termini named; and on the other hand, one obligation assumed by the State was that it would not prevent the company from so constructing and operating the road. If the charter had in terms granted to the corporation power to charge and collect a definite sum per mile for the transportation of persons or of property, it would not be doubted that that express stipulation formed a part of the obligation of the State which it could not repudiate. Whether, in the absence of an express stipulation of that character, there is not implied in the grant of the right to construct and operate, the grant of a right to charge and collect such tolls as will enable the company to successfully operate the road and return some profit to those who have invested their money in the construction, is a question not as yet determined. It is at least a question which arises as to the extent to which that contract goes, and one in which the corporation has a right to invoke the judgment of the courts; and if the corporation, a citizen of the State, has the right to maintain a suit for the determination of that question, clearly a citizen of another State, who has, under authority of the laws of the State of Texas, become pecuniarily interested in, equitably indeed the beneficial owner of, the property of the corporation, may invoke the judgment of the Federal courts as to whether the contract rights created by the charter, and of which it is thus the beneficial owner, are violated by subsequent acts of the State in limitation of the right to collect tolls. Our conclusion from these considerations is that the objection to the jurisdiction of the Circuit Court is not tenable, and this, whether we rest upon the provisions of the statute or upon the general jurisdiction of the court existing by virtue of the statutes of Congress, under the sanction of the Constitution of the United States. Passing from the question of jurisdiction to the act itself, there can be no doubt of the general power of a State to regu Opinion of the Court. late the fares and freights which may be charged and received by railroad or other carriers, and that this regulation can be carried on by means of a commission. Such a commission is merely an administrative board created by the State for carrying into effect the will of the State as expressed by its legislation. Railroad Commission Cases, 116 U. S. 307. No valid objection, therefore, can be made on account of the general features of this act; those by which the State has created the railroad commission and entrusted it with the duty of prescribing rates of fares and freights as well as other regulations for the management of the railroads of the State. Specific objections are made to the act, on the ground that, by section 5, the rates and regulations made by the commission are declared conclusive in all actions between private individuals and the companies, and that by section 14 excessive penalties are imposed upon railroad corporations for any violation of the provisions of the act; and thus, as claimed, there is not only a limitation but a practical denial to railroad companies of the right of a judicial inquiry into the reasonableness of the rates prescribed by the commission. The argument is, in substance, that railroad companies are bound to submit to the rates prescribed until in a direct proceeding there has been a final adjudication that the rates are unreasonable, which final adjudication, in the nature of things, cannot be reached for a length of time; that meanwhile a failure to obey those regulations exposes the company, for each separate fare or freight exacted in excess of the prescribed rates, to a penalty so enormous as in a few days to roll up a sum far above the entire value of the property; that even if in a direct proceeding the rates should be adjudged unreasonable, there is nothing to prevent the commission from reëstablishing rates but slightly changed and still unreasonable, to set aside which requires a new suit, with its length of delay; and thus, as is claimed, the railroad companies are tied hand and foot and bound to submit to whatever illegal, unreasonable, and oppressive regulations may be prescribed by the commission. It is enough to say in respect to these matters, at least so Opinion of the Court. far as this case is concerned, that it is not to be supposed that the legislature of any State, or a commission appointed under the authority of any State, will ever engage in a deliberate attempt to cripple or destroy institutions of such great value to the community as the railroads, but will always act with the sincere purpose of doing justice to the owners of railroad property, as well as to other individuals; and also that no legislation of a State, as to the mode of proceeding in its own courts, can abridge or modify the powers existing in the Federal courts, sitting as courts of equity. So that if in any case, there should be any mistaken action on the part of a State, or its commission, injurious to the rights of a railroad corporation, any citizen of another State, interested directly therein, can find in the Federal court all the relief which a court of equity is justified in giving. We do not deem it necessary to pass upon these specific objections because the fourteenth section or any other section prescribing penalties may be dropped from the statute without affecting the validity of the remaining portions; and if the rates established by the commission are not conclusive, they are at least prima facie evidence of what is reasonable and just. For the purpose of this case it may be conceded that both the clauses are unconstitutional, and still the great body of the act remains unchallenged that which establishes the commission, and empowers it to make reasonable rates and regulations for the control of railroads. It is familiar law that one section or part of an act may be invalid without affecting the validity of the remaining portion of the statute. Any independent provision may be thus dropped out if that which is left is fully operative as a law, unless it is evident from a consideration of all the sections that the legislature would not have enacted that which is within, independently of that beyond its power. - Applying this rule, the invalidity of these two provi sions may be conceded without impairing the force of the rest of the act. The creation of a commission, with power to establish rules for the operation of railroads and to regulate rates, was the prime object of the legislation. This is fully accomplished whether any penalties are imposed for a viola Opinion of the Court. tion of the rules prescribed, or whether the rates shall be conclusive or simply prima facie evidence of what is just and reasonable. The matters of penalty and the effect as evidence of the rates are wholly independent of the rest of the statute. Neither can it be supposed that the legislature would not have established the commission and given it power over railroads without these independent matters. In other words, it is not to be presumed that the legislature was legislating for the mere sake of imposing penalties, but the penalties and the provision, as to evidence, were simply in aid of the main purpose of the statute. They may fail, and still the great body of the statute have operative force, and the force contemplated by the legislature in its enactment. Take a similar body of legislation—a tax law. There may be incorporated into such a law a provision giving conclusive effect to tax deeds, and also a provision as to the penalties incurred by non-payment of taxes. These two provisions may, for one reason or another, be obnoxious to constitutional objections. If so, they may be dropped out, and the balance of the statute exist. It would not for a moment be presumed that the whole tax system of the State depended for its validity upon the penalties for non-payment of taxes or the effect to be given to the tax deed. We, therefore, for the purposes of this case, assume that these two provisions of the statute are open to the constitutional objections made against them. We do not mean by this to imply that they are so in fact, but simply that it is unnecessary to consider and determine the matter, and we leave it open for future consideration. It appears from the bill that, in pursuance of the powers given to it by this act, the state commission has made a body of rates for fares and freights. This body of rates, as a whole, is challenged by the plaintiff as unreasonable, unjust, and working a destruction of its rights of property. The defendant denies the power of the court to entertain an inquiry into that matter, insisting that the fixing of rates for carriage by a public carrier is a matter wholly within the power of the legislative department of the government and beyond examination by the courts. Opinion of the Court. It is doubtless true, as a general proposition, that the forma tion of a tariff of charges for the transportation by a common carrier of persons or property is a legislative or administrative rather than a judicial function. Yet it has always been recognized that, if a carrier attempted to charge a shipper an unreasonable sum, the courts had jurisdiction to inquire into that matter and to award to the shipper any amount exacted from him in excess of a reasonable rate; and also in a reverse case to render judgment in favor of the carrier for the amount found to be a reasonable charge. The province of the courts is not changed, nor the limit of judicial inquiry altered, because the legislature instead of the carrier prescribes the rates. The courts are not authorized to revise or change the body of rates imposed by a legislature or a commission; they do not determine whether one rate is preferable to another, or what under all circumstances would be fair and reasonable as between the carriers and the shippers; they do not engage in any mere administrative work; but still there can be no doubt of their power and duty to inquire whether a body of rates prescribed by a legislature or a commission is unjust and unreasonable, and such as to work a practical destruction to rights of property, and if found so to be, to restrain its operation. In Chicago, Burlington & Quincy Railroad v. Iowa, 94 U. S. 155, and Peik v. Chicago & Northwestern Railway, 94 U. S. 164, the question of legislative control over railroads was presented, and it was held that the fixing of rates was not a matter within the absolute discretion of the carriers, but was subject to legislative control. As stated by Mr. Justice Miller, in Wabash &c. Railway v. Illinois, 118 U. S. 557, 569, in respect to those cases: "The great question to be decided, and which was decided, and which was argued in all those cases, was the right of the State, within which a railroad company did business, to regulate or limit the amount of any of these traffic charges." There was in those cases no decision as to the extent of control, but only as to the right of control. This question came again before this court in Railroad Commission Cases, 116 U. S. 307, 331, and while the right of control was re |