A similar question was before us at the last term, in Cincinnati, N. O. & T. P. Ry. Co. v. Interstate Commerce Commission, 162 U.S. 184, 16 Sup. Ct. 700, and in the opinion, on pages 196 and 197, 162 U.S., and page 705, 16 Sup. Ct., we said:
'Whether congress intended to confer upon the interstate commerce commission the power to itself fix rates was mooted in the courts below, and is discussed in the briefs of counsel.
'We do not find any provision of the act that expressly, or by necessary implication, confers such a power.
'It is argued on behalf of the commission that the power to pass upon the reasonableness of existing rates implies a right to prescribe rates. This is not necessarily so. The reasonableness of the rate in a given case depends on the facts, and the function of the commission is to consider these facts and give them their proper weight. If the commission, instead of withholding judgment in such a matter until an issue shall be made and the facts found, itself fixes a rate, that rate is prejudged by the commission to be reasonable.
'We prefer to adopt the view expressed by the late Justice Jackson, when circuit judge, in the case of Interstate Commerce Commission v. Baltimore & O. R. Co., 43 Fed. 37, and whose judgment was affirmed by this court. 145 U.S. 263, 12 Sup. Ct. 844.
"Subject to the two leading prohibitions, that their charges shall not be unjust or unreasonable, and that they shall not unjustly discriminate, so as to give undue preference or disadvantage to persons or traffic similarly circumstanced, the act to regulate commerce leaves common carriers as they were at the common law,-free to make special contracts looking to the increase of their business, to classify their traffic, to adjust and apportion their rates so as to meet the necessities of commerce, and generally to manage their important interests upon the same principles which are regarded as sound, and adopted, in other trades and pursuits." The views thus expressed have been vigorously and earnestly challenged in this and in other cases argued at the present term. In view of its importance, and the full arguments that have been presented, we have deemed it our duty to re-examine the question in its entirety, and to determine what powers congress has given to this commission in respect to the matter of rates. The importance of the question cannot be overestimated. Billions of dollars are invested in railroad properties. Millions of passengers, as well as millions of tons of freight, are moved each year by the railroad companies, and this transportation is carried on by a multitude of corporations working in different parts of the country, and subjected to varying and diverse conditions.
Before the passage of the act it was generally believed that there were great abuses in railroad management and railroad transportation, and the grave question which congress had to consider was how those abuses should be corrected, and what control should be taken of the business of such corporations. The present inquiry is limited to the question as to what it determined should be done with reference to the matter of rates. There were three obvious and dissimilar courses open for consideration. Congress might itself prescribe the rates, or it might commit to some subordinate tribunal this duty, or it might leave with the companies the right to fix rates, subject to regulations and restrictions, as well as to that rule which is as old as the existence of common carriers, to wit, that rates must be reasonable. There is nothing in the act fixing rates. Congress did not attempt to exercise that power, and, if we examine the legislative and public history of the day, it is apparent that there was no serious thought of doing so.