Mr. Justice Sutherland
delivered the opinion of the Court.
The question presented for determination by these appeals is the constitutionality of the Act of September 19, 1918, providing for the fixing of minimum wages for women and children in the District of Columbia. 40 Stat. 960, c. 174.
The act provides for a board of three members, to be constituted, as far as practicable, so as to be equally repre-. [540]*540.sehtative of employers, employees and the public. The board is authorized to have public hearings, at which persons interested in the matter being investigated may appear and testify, to administer oaths, issue subpoenas requiring the attendance of witnesses and production of books, etc., and to make rules and regulations for carrying the act into effect.
By § 8 the board is authorized—
“(1), To investigate and ascertain the wages of women and minors in the different occupations in which they are employed, in the District of Columbia; (2), to examine, through any member or authorized representative, any book, pay roll or other record of any employer of women or minors that in any way appertains to or has a bearing upon the question of wages of any such women or,minors; and (3), to require from such employer full and true statements of the wages paid to all women and minors in his employment.”.
And by § 9, “■ to ascertain and declare, in the manner hereinafter provided, the following things: (a), Standards of minimum wages for women in any occupation within the District of Columbia, and-what wages are inadequate to supply the necessary cost of living to any such women workérs to maintain them in good health and to protect their morals; and (b), standards of minimum wages for minors in any occupation within the District of Columbia, and what wages are unreasonably low for any such minor workers.” .
The act then provides (§ 1Ó) that if the board, after investigation, is of opinion that any substantial number of women workers in any occupation are receiving wages inadequate to supply them with the necessary cost of living, maintain them in health and protect their morals, a conference may be called to consider and inquire into and report on the subject investigated, the conference to be equally representative pf employers and employees in [541]*541such occupation and of the public, and to include one or more members of the board.
The conference is required to make and transmit to' the board a report including, among other things, “ recommendations as to standards of minimum wages for women workers in the occupation under inquiry and as to what wages are inadequate to supply the necessary cost of living to women workers in such occupation and to maintain them in health and to protect their morals.” § 11.
The board is authorized (.§ 12) to consider and review these recommendations and to approve or disapprove any or all of them. If it approve any recommendations it must give public notice of its intention and hold a public hearing at which the persons interested will be heard. After such hearing, the board is authorized to make such order as to it may appear necessary to carry into effect the recommendations, and to require all employers in the occupation affected to comply therewith. It is made unlawful for any such employer to violate in this regard any provision of the order or to employ any woman worker at lower wages than are thereby permitted.
There is a provision (§13) under which the board may issue a special license to a woman whose earning capacity “ has been impaired by age or otherwise,” authorizing her employment at less than the minimum wages fixed under the act.-
All questions of fact (§ 17) are to be determined by the board, from whose decision there is no appeal; but an appeal is .allowed on questions of law.
Any violation of the act (§ 18) by an employer or his agent or by corporate agents is declared to be a misdemeanor, punishable by fine and imprisonment.
Finally, after some further provisions not necessary to be stated, it is declared (§ 23) that the purposes of the act are “ to protect the women and minors of the District [542]*542from conditions detrimental to their health and morals, resulting from wages which are inadequate to maintain decent standards of living; and the Act in each of its provisions and in its entirety shall be interpreted to effectuate these purposes.”
The appellee in the first case is a corporation maintaining a hospital for children in the District. . It employs a large number of women in various capacities, with whom it had agreed upon rates of wages and compensation satisfactory to such employees, but which in some instances were less than the minimum wage fixed by an order of the board made in pursuance of the act. The women with whom appellee had so contracted were all of full age and under no legal disability. The instant suit was brought ..by, the appellee in the Supreme Court of the District to- restrain the board from enforcing or attempting. to, enforce its order on the ground that the same was in. contravention of the Constitution, and particularly the due process clause of the Fifth Amendment.
In the second case the appellee, a woman twenty-one years of age, was .employed by the Congress Hall Hotel Company as an elevator operator, at a salary of $35 per month and two - meals a day. She alleges that the work was light and healthful, the hours short, with surroundings clean and moral, and that she was anxious to continue it for the compensation she was receiving and that she did not earn more. Her services were satisfactory to the Hotel Company and it would have been glad to retain her but was obliged to dispense with her sei-vices by reason of the order of the board and on account of the penalties prescribed by the act. The wages received- by this appellee were the best she was able to obtain for any work she was capable of performing and the enforcement of the order, she alleges, deprived, her of such employment and wages. She further averred that she could not secure any other position at which she could make a living, with [543]*543as good physical and moral surroundings, and earn as good wages, and that she was desirous of continuing and would continue the employment but for the order of the board. An injunction was prayed as in the other case.
The Supreme Court of the District denied the ’injunction and dismissed the bill in each case. Upon appeal the Court of Appeals by a majority first affirmed and subsequently, on a rehearing, reversed the trial court. Upon the first argument a justice of the District Supreme Court was called in to take the place of one of the Appellate Court justices, who was ill. Application for rehearing was made and, by the court as thus constituted, was denied. Subsequently, and during the term, a rehearing was granted by an order concurred in by two of the Appellate Court justices, one being the justice whose place on the prior occasion had been filled by the Supreme Court member. Upon the rehearing thus granted, the Court of Appeals, rejecting the first opinion, held the act in question to be unconstitutional and reversed the decrees of the trial court. Thereupon the cases were remanded, and the trial court entered decrees in pursuance of the mandate, declaring the act in question to be unconstitutional and granting permanent injunctions. Appeals to the Court of Appeals followed and the decrees of the trial court were affirmed. It is from these final decrees that the cases come here.
Upon this state of facts the jurisdiction of the lower court to grant a rehearing, after first denying it, is challenged. We do not deem it necessary to consider the matter farther than to say that we are here dealing with the second appeals, whilé the proceedings complained of occurred upon the first appeals. That the lower court could properly entertain the second appeals and decide the cases does not admit of doubt; and this the appellants virtually conceded by having themselves invoked the jurisdiction. See Rooker v. Fidelity Trust Co., ante, 114.
[544]*544We come then, at once, to the substantive question involved.
The judicial duty of passing upon the constitutionality of an act of Congress is one of great gravity and delicacy. The statute here in question has successfully borne the scrutiny of the. legislative branch of the government, which, by enacting it, has affirmed its validity; and that determination must be given great weight. This Court, by an unbroken line of decisions from Chief Justice Marshall to the present day, has steadily adhered to the rule that every possible presumption is in favor of the validity of an act of Congress until overcome beyond rational doubt. But if by .clear and indubitable demonstration a statute be opposed to the Constitution we have no choice but to say- so. The Constitution, by its own ternas, is-the supreme law of the land, emanating from the people, the . repository of ultimate sovereignty under our form of government. A congressional statute, on the other hand, is the act of an agency of this sovereign authority and if it conflict with the' Constitution must fall; for that which is not supreme must yield to that which is. To hold it invalid (if it be invalid) is a plain exercise of the judicial power — that power vested in courts to enable them to administer justice according to law. From the authority to ascertain and determine the law in a given case, there necessarily results, in case of conflict, the duty to declare and enforce the rule of the supreme law and reject that of an inferior act of legislation which, transcending the Constitution, is of no effect and binding on no one. This is not the exercise of a substantive power to review and nullify acts of-Congress, for no such substantive power exists. It is simply a necessary concomitant of the power to hear and dispose of a case or controversy properly before the court, to the determination, of which must be brought the test and measure of the law.
[545]*545The statute now under consideration is ¿ttacked upon the ground that it authorizes an unconstitutional inter-' ference with the freedom of contract included within the guaranties of the due process clause of the Fifth Amendment. That the right to contract about one’s affairs is a part of the liberty of the individual protected by this clause, is settled by the decisions of this Court and is no longer open to question. Allgeyer v. Louisiana, 165 U. S. 578, 591; New York Life Insurance Co. v. Dodge, 246 U. S. 357, 373-374; Coppage v. Kansas, 236 U. S. 1, 10, 14; Adair v. United States, 208 U. S. 161; Lochner v. New York, 198 U. S. 45; Butchers’ Union Co. v. Crescent City Co., 111 U. S. 746; Muller v. Oregon, 208 U. S. 412, 421. Within this liberty are contracts of employment of labor. In making such contracts, generally speaking, the parties have an equal right to obtain from each other the best terms they can as the result of private bargaining.
In Adair v. United States, supra, Mr. Justice Harlan (pp. 174,175), speaking for the Court, said:
“ The right of a person to sell his labor upon such terms as he deems proper is, in its essence, the same as the right of the purchaser of labor to prescribe the conditions upon which he will accept such labor from the person offering to sell. ... In all such particulars the employer and employe have equality of right, and any legislation that disturbs that equality is an arbitrary interference with the liberty of contract which no government can legally justify in a free land.”
In Coppage v. Kansas, supra (p. 14), this Court, speaking through Mr. Justice Pitney, said:
“ Included in the right of personal liberty and the right of private property — partaking of the nature of each — is the right to make contracts for the acquisition of property. Chief among such contracts is that of personal employment, by which labor and other services are exchanged for money or other forms of property. If this [546]*546right be struck down or arbitrarily interfered with, there is a substantial impairment of liberty in the long-established constitutional sense. The right is as essential to the laborer as to the capitalist, to the poor as to the rich; for the vast majority of persons have no other honest way to begin to acquire property, save by working for money.
“An interference with this liberty so serious as that now under consideration, and so disturbing of equality of right, must be deemed to be arbitrary, unless it be supportable as a reasonable-exercise of the police power of the State.”
There is, of course, no such thing as absolute freedom of contract. It is subject to a great variety of restraints. But freedom of contract is, nevertheless, the general rule and restraint the exception; and the exercise of legislative authority to abridge it can be justified only by the existence of exceptional circumstances. Whether these circumstances exist in the present case constitutes the question to be answered. It will be helpful to this end to review some of the decisions where the interference has been upheld and consider the grounds upon which they rest.-
(1) Those dealing with statutes fixing rates and charges to he exacted by businesses impressed with a public interest. There are many cases, but it is sufficient to cite Munn v. Illinois, 94 U. S. 113. The power here rests upon the ground that where property is devoted to a public use the owner thereby, in effect, grants to the public an interest in the use which may be controlled by the public for the common good to the extent of the interest thus created. It is upon this theory that these statutes have been upheld and, it may be noted in passing, so upheld even in respect of their incidental and injurious or destructive effect upon preexisting contracts. See Louisville & Nashville R. R. Co. v. Mottley, 219 U. S. 467. In the case at bar the statute does not depend upon [547]*547the existence of a public interest in any business to be affected, and this class of cases may be laid aside as inapplicable.
(2) Statutes relating to contracts for the performance of public work. Atkin v. Kansas, 191 U. S. 207; Heim v. McCall, 239 U. S. 175; Ellis v. United States, 206 U. S. 246. These cases sustain such statutes as depending, not upon the right to condition private contracts, but upon the right of the government to prescribe the- conditions upon which it will permit work of a public character to be done for it, or, in the case of a State, for its municipalities. We may, therefore, in like manner, dismiss these decisions from consideration as inapplicable.
. (3) Statutes prescribing the character, methods and time for, payment of wages. Under this head may be included McLean v. Arkansas, 211 U. S. 539, sustaining a state statute-requiring coal to be measured for payment of miners’ wages before screening; Knoxville Iron Co. v. Harbison, 183 U. S. 13, sustaining a Tennessee statute requiring the redemption in cash of store orders issued in payment of wages; Erie R. R. Co. v. Williams, 233 U. S. 685, upholding a statute regulating the time within which wages shall be paid to employees in certain specified industries; and other cases sustaining statutes of like import and effect. In none of the statutes thus sustained, was the liberty of employer or employee to fix the amount of-wages the one was willing to pay and the other willing to receive interfered with. Their tendency and purpose was to prevent unfair and perhaps fraudulent methods in the payment of wages and in no sense can they be said to be, or to furnish a precedent for, wage-fixing statutes.
(4) Statutes fixing hours of labor. It is upon this class that the greatest emphasis is laid in argument and therefore, and because such cases approach most nearly the line of principle applicable to the statute here involved, we shall consider them more at length. In some instances [548]*548the statute limited the hours of- labor for men in certain occupations and in others it was confined in its application to women. No statute has thus far been brought to the attention of this Court which by its terms, applied to all occupations. In Holden v. Hardy, 169 U. S. 366, the Court considered an act of the Utah legislature, restricting the hours of labor in 'mines and smelters. This statute was sustained as a legitimate exercise of the police power, on the ground that the legislature had determined that these particular employments, when too long pursued, were injurious to the health of the employees, and that, as there were reasonable grounds for supporting this determination on the part of the legislature, its decision in that respect was beyond the reviewing power of the federal courts.
■ That this constituted the basis of the decision is emphasized by the subsequent decision in Lochner v. New York, 198 U. S. 45, reviewing a state statute which restricted the employment of all persons in bakeries to ten hours in any one day. The Court referred to Holden v. Hardy, supra, and, declaring it to be inapplicable, held the statute unconstitutional as an unreasonable, unnecessary and arbitrary interference with the liberty of contract and therefore void under the Constitution.
Mr. Justice Peckham, speaking for the Court (p. 56), said:
“ It must, of course, be conceded that there is a limit to the valid exercise of the police power by the State. There is no dispute concerning this general proposition. Otherwise the Fourteenth Amendment would have no efficacy and the legislatures of the States would have unbounded power, and it would be enough to say that any piece of legislation was enacted to conserve the morals, the health or the safety of the people; such legislation would be valid, no matter how absolutely without foundation the claim might be. The claim of the police power [549]*549would be a mere pretext — become' another and delusive name for the supreme sovereignty of the State to be exercised free from constitutional restraint.”
And again (pp. 57-58):
“ It is a question of which of two powers or rights shall prevail — the power of the State to legislate or the right of the individual to liberty of person and freedom of contract. The mere assertion that the subject relates though but in a remote degree to the public health does not necessarily render the enactment valid. The act must have a more direct relation, as a means to an end, and the end itself must be appropriate and legitimate, before an act can be held to be valid which interferes with the general right of an individual to be free in his person and in his power to contract in relation to his own labor.” '
Coming then directly to the statute (p. 58), the Court said:
“We think the limit of the police power has been reached and passéd in this case. There is, in our judgment, no reasonable foundation for holding this to be necessary or appropriate as a health law to safeguard the public health or the health of the individuals who are following the trade of a baker. If this statute be valid, and if, therefore, a proper case is made out in which to deny the right of an individual, sui juris, as employer or employé, to make contracts for the labor of the latter under the protection of the provisions of the Federal Constitution, there would seem to be no length to which legislation of this nature might not go.”
And, after pointing out the unreasonable range to which the principle of the statute might be extended, the Court said (p. 60):
' “ It is also urged, pursuing the same line of argument, that it is to the interest of the State that its population should be strong and robust, and therefore any legislation which may be said to tend to make people healthy must [550]*550be valid as health laws, enacted under the police power. If this be a valid argument and a justification for this kind of legislation, it follows that the protection of the Federal Constitution from undue interference with liberty of person and freedom of contract is visionary, wherever the law is sought to be justified as a valid exercise of the police power. Scarcely any law but might find shelter under such assumptions, and conduct, properly so called, as well as contract, would come under the restrictive sway of the legislature.”
And further (p. 61):
“ Statutes of the nature of that under review, limiting the hours in which grown and intelligent men may labor to earn their living, are mere meddlesome interferences with the rights of the individual, and they are not saved from condemnation by the claim that they are passed in the exercise of the police power and upon the subject of the health of the individual whose rights are interfered with, unless there be some fair ground, reasonable in and of itself, to say that there is material danger to the public health or to the health of the employes, if the hours of labor are not curtailed.”
Subsequent cases in this Court have been distinguished from that decision, but the principles therein stated have never been disapproved.
In Bunting v. Oregon, 243 U. S. 426, a state statute forbidding the employment of any person in any mill, factory or manufacturing establishment more than ten hours in any one day, and providing payment for overtime not exceeding three hours in any one day at the rate of time and a half of the regular wage, was sustained on the ground that, since the state legislature and State Supreme Court had found such a law necessary for the preservation of the health of employees in these industries, this Court would accept their judgment, in the absence of facts to support the contrary conclusion. The law was attacked [551]*551on the ground that it constituted an attempt to fix wages, but that contention was rejected and the law sustained as a reasonable regulation of hours of service.
Wilson v. New, 243 U. S. 332, involved the validity of the so-called Adamson Law, which established an eight-hour day for employees of interstate carriers for which it fixed a scale of minimum wages with proportionate increases for overtime, to be enforced, however, only for a limited period. The act was sustained primarily upon the ground that it was a regulation of a business charged with a public interest. The Court, speaking through the Chief Justice, pointed out that regarding “ the private right and private interest as contradistinguished from the public interest the power exists between the parties, the employers and employees, to agree as to a standard of wages free from legislative interference ” but that this did not affect the power to deal with the matter with a view to protect the public right, and then said (p. 353):
“And this emphasizes that there is no question here of purely private right since the law is concerned only with those who are engaged in a business charged with a public interest where the subject dealt with as to all the parties is one involved in that business and which we have seen comes under the control of the right to regulate to the extent that the power to do so is appropriate or relevant to the business regulated.”
Moreover, in sustaining the wage feature, of the law, emphasis was put upon the fact (p. 345) that it was in this respect temporary “ leaving the employers and employees free as to the subject of wages to govern their relations by their own agreements after the specified time.” The act was not only temporary in this respect, but it was passed to meet a sudden and great emergency. This feature of the law was sustained principally because the parties, for the time being, could not or would not agree. Here they are forbidden to agree.
[552]*552The same principle was applied in the Rent Cases (Block v. Hirsh, 256 U. S. 135, and Marcus Brown Holding Co. v. Feldman, 256 U. S. 170), where this Court sustained the legislative power to fix- rents as between landlord and tenant upon the ground that the operation of the statutes was temporary to tide over an emergency and that the circumstances were such as to clothe “ the letting of buildings . . . with a public interest so great as to justify regulation by law.” The Court said (P- 157): .
“ The regulation is put and justified only as a tempo-, racy measure [citing Wilson v. New, supra]. A limit in time, to tide over a passing trouble, well may justify a law that could not be upheld as a permanent change.”
In a subsequent case, Pennsylvania Coal Co. v. Mahon, 260 U. S. 393, 416, this Court, after saying “ We are in danger of forgetting that a strong public desire to improve the public condition is not enough to warrant achieving the desire by a shorter cut than the constitutional way of paying for the change,” pointed out that the Rent Cases dealt with laws intended to meet a temporary emergency and “ went to the verge of the law.”
In addition to the cases cited above, there are the decisions of this Court dealing with laws especially relating to hours of labor for women: Muller v. Oregon, 208 U. S. 412; Riley v. Massachusetts, 232 U. S. 671; Miller v. Wilson, 236 U. S. 373; Bosley v. McLaughlin, 236 U. S. 385.
In the Muller Case the validity of an Oregon statute, forbidding the employment of any female in certain industries more than ten hours during any one day was upheld. The decision proceeded upon the theory that the difference between the sexes may justify a different rule respecting hours of labor in the case of women than in the case of men. It is pointed out that these consist in differences of physical structure, especially in respect [553]*553of the maternal functions, and also in the fact that historically woman has always been dependent upon man, who has established his control by superior physical strength. The cases of Riley, Miller and Bosley follow in this respect the Muller Case. But the ancient inequality of the sexes, otherwise than physical, as-suggested in the Muller Case (p. 421) has continued “with diminishing intensity.” In view of the great — not to say revolutionary — changes which have taken place since that utterance, in the contractual, political and civil status of women, culminating in the Nineteenth Amendment, it is not unreasonable to say that these differences have now come almost, if not quite, to the vanishing point. In this aspect of the matter, while the physical differences must be recognized in appropriate cases, and legislation fixing hours or conditions of, work may properly take them into account, we cannot accept the doctrine that women of mature age, sui juris, require or may be subjected to restrictions upon their liberty of contract which could not lawfully be imposed in the case of men under similar circumstances. To do so would be to ignore all the implications to be drawn from the present day trend of legislation, as well as that of common thought and usage, by which woman is accorded emancipation from the old doctrine that she must be given special protection or be subjected to special restraint in her contractual and civil relationships. In passing, it may be noted that the instant statute applies in the case of a woman employer contracting with a woman employee as it does when the former is a man.
The essential characteristics of the statute.now under consideration, which differentiate it from the laws fixing'' hours of labor,-will be made to appear as we proceed. It is sufficient now to point out that the latter as well as the statutes mentioned under paragraph (3), deal with incidents of the employment having no necessary effect upon [554]*554the heart of the contract, that is, the amount of wages to be paid and received. A law forbidding work to continue beyond a given number of hours leaves the parties free to contract about wages and thereby equalize whatever additional burdens may be imposed upon the employer as a result of the restrictions as to hours, by an adjustment in respect of the amount of wages. Enough has been said to show that the authority to fix hours of labor cannot be exercised except in respect of those occupations where work of long continued duration is detrimental to health. This Court has been careful in every case where the question has been raised, to place its decision upon this limited authority of the legislature to regulate hours of labor and to disclaim any purpose to uphold the legislation as fixing wages, thus recognizing an essential difference between the two. It seems plain that these decisions afford no real support for any form of law establishing minimum wages.
If now, in the light furnished by the foregoing exceptions to the' general rule forbidding legislative interference with freedom of contract, we examine and analyze the statute in question, we shall see that it differs from them in every material respect. It is not a law dealing with any business charged with a public interest or with public work, or to meet and tide over a temporary emergency. Jt has nothing to do with the character, methods or periods of wage payments. It does not prescribe hours of labor or conditions under which labor is to be done. It is not for the protection of persons under legal disability, or for the prevention of fraud. It is simply and exclusively a price-fixing law, confined to adult women (for we are not now considering the provisions relating to minors), who are legally as capable of contracting for themselves as men. It forbids two parties having lawful capacity — under penalties .as to the employer — to freely contract with-one another in respect of the price for [555]*555which one shall render service to the other in a purely private employment where both are willing, perhaps anxious, to agree, even though the consequence may be to oblige one to surrender a desirable engagement and the other to dispense with the services of a desirable employee.1 The price fixed by the board need have no relation to the capacity or earning power of the employee, the numben pf hours which may happen to. constitute the day’s work, -the character of the place where the work is to be done, or the circumstances or surroundings of the employment; and, while it has no other basis to support its validity than the assumed necessities of the employee, it takes no account of any independent resources she may have. It is based wholly on the opinions of the members of the board and their advisers — perhaps an average of their opinions, if they do not precisely agree — as to what will be necessary to provide a living for a woman, keep her in health and preserve her morals. It applies to any and every occupation in the District, without regard to its nature or the character of the work.
The standard furnished by the statute for the guidance of the board is so vague as to be .impossible of practical application with any reasonable degree of accuracy. What is sufficient to supply the necessary cost of living for a woman worker and maintain her in good .health and protect her morals is obviously not a precise or unvarying sum — not even approximately so. The amount will depend upon a variety of circumstances: the individual temperament, habits of thrift, care, ability to buy necessaries intelligently, and whether the woman live alone or with her family. To those who practice economy, a given sum will afford comfort, while to those of contrary habit the same sum will be wholly inadequate.- The cooperative economies of the family group are not taken into account [556]*556though they constitute an important consideration in estimating the cost of living, for it is obvious that' the individual expense will be less in the case of a member of a family than in the case of one living alone. The relation between earnings and morals is not capable of standardization. It cannot be shown that well paid women • safeguard their morals more carefully than those who are poorly paid. Morality rests upon other considerations than wages; and there is, certainly, no such prevalent connection between the two as to justify a broad attempt to adjust the latter with reference to the former. As a means of safeguarding morals the attempted classification, in our opinion, is without reasonable basis. No distinction can be made between women who work for others and those who do not; nor is there ground for distinction between women and men, for, certainly, if women require a minimum wage to preserve their morals men require it to preserve their honesty. For these reasons, and others which might be stated, the inquiry in respect of the-necessary cost, of living and of the income necessary to preserve health-and morals, presents an individual and not a composite question, and must be answered for each individual considered by herself and not by a general formula prescribed by a statutory bureau.
This uncertainty of the statutory standard is demonstrated by a consideration of certain orders of the board already made. These orders fix the sum to be paid to a' woman employed in a place where food is served or in. a mercantile establishment, at $16.50 per week; in a printing establishment, at $15.50 per week; and in a.laundry, at $15 per week, with a provision reducing this to $9 in the case of a beginner. If a woman employed to serve food requires a minimum of $16.50 per week, it is hard to understand how the same.woman working in a printing establishment or in a laundry is to get on with an income lessened by from .$1 to $7.50 per week. The board prob[557]*557ably found it impossible to follow the indefinite standard of the' statute, and brought other and different factors into the problem; and this goes far in the direction of demonstrating the fatal uncertainty of the act, an infirmity which, in our opinion, plainly exists.
The law takes account of the necessities of only one party to the contract. It ignores the necessities of the employer by compelling him to pay not less than a certain-sum, not -only whether the employee is capable of earning it, but irrespective of the ability of his business to sustain the burden, generously leaving him, of course, the privilege of abandoning his business as.an alternative for going on at a loss. Within the limits of the minimum sum, he is precluded, under penalty of fine and imprisonment, from adjusting compensation to the differing merits of his employees. It compels him to pay at least the sum-fixed in any event, because the employee needs it, but requires no service of equivalent value from the employee. • It therefore undertakes to solve but one-half of the problem. The other half is the establishment of a corresponding standard -of efficiency, and this forms no part of the policy of the legislation, although in practice the former half without the latter must lead to ultimate failure, in accordance with the inexorable law that no one can continue indefinitely, to take out more than he puts in without ultimately exhausting the supply.- The law' is not confined to the great and powerful employers but embraces those whose bargaining power may be as weak as that of the employee. It takes no account of periods of stress and business depression, of crippling losses, which may leave the employer himself without adequate means of livelihood. To the extent that the sum fixed exceeds the fair value of the service's rendered, it amounts to a compulsory exaction from the employer for the support of a partially indigent person, for whose condition there [558]*558rests upon him no peculiar responsibility, and therefore, in effect, arbitrarily shifts to his shoulders'a burden which, if it belongs to anybody, belongs to society as a whole.
The feature of this statute which, perhaps more than' any other, puts upon it the stamp of invalidity is that it exacts from the employer an arbitrary payment for a purpose and upon a basis having no causal connection with his business, or the contract or the work the employee engages to do. The declared basis, as already pointed out, is not the value of the service rendered, but the extraneous circumstance that the employee needs to get a prescribed sum of money to insure her subsistence, health and morals. The ethical right of every worker, man or woman, to a living wage may be conceded. One of the declared and important purposes of trade organizations is to secure it. And with that principle and with every legitimate .effort to realize it in fact, no one can quarrel; but the fallacy of the proposed method of attaining it is that it assumes that every employer is bound at all events to furnish it. The moral requirement implicit in every contráct of employment, viz, that the amount to be paid and thev service to be rendered shall bear to each other some relation of just equivalence, is completely ignored. The necessities of the employee are alone considered and these arise outside of the employment, are the same when there is no employment, and as great in one occupation as in another. Certainly the employer by paying a fair. equivalent for the service rendered, though, not sufficient to support the employee, has neither caused nor contributed to her poverty. On the contrary, to the extent of what he pays he has relieved it. In principle, there can be no difference between the case of selling labor and the case of selling goods. If one goes to the butcher, the baker or grocer to buy food, he is morally entitled to obtain the worth of his money but he is 'riot entitled to more, If what he gets is worth what he pays he is not justified in demanding [559]*559more simply because he needs more; and the shopkeeper, having dealt fairly ánd honestly in that transaction, is not concerned in any peculiar sense with the question of his customer’s necessities. Should a statute undertake to vest in a commission power to determine the quantity of food necessary for individual support and require the shopkeeper, if he sell to the individual at all, to furnish that quantity at not more than a fixed maximum, it would undoubtedly fall before the constitutional test. The fallacy of any argument in support of the validity of such a statute would be quickly exposed. The argument in support of that now being considered is equally fallacious, though the weakness of it may not be so plain. A statute requiring an employer to pay in money, to pay at prescribed and regular intervals, to pay the value of the services rendered,, even to pay with fair relation to the extent of the benefit obtained from the service, would be understandable. But a statute which prescribes payment without regard to any of these things and solely .with relation to circumstances apart from the contract of employment, the business affected by it and the work done under it, is so clearly the product of a naked, arbitrary exercise of power that it cannot be allowed to stand under the Constitution of the United States.
We are asked, upon the one hand, to consider the fact that several States have adopted similar statutes, and we are invited, upon the other hand, to give weight to the fact that three times as many States, presumably as well informed and as anxious to promote the health and morals of their people, have refrained from enacting such legislation. We have also been furnished with a large number of printed opinions approving the policy of the minimum wage, and our own reading has disclosed a large number to the contrary. These are all proper enough for the. consideration of the layunaking bodies, since their tendency is to establish the desirability or undesirability of the [560]*560legislation; but they reflect no legitimate light upon the question of its -validity, and that- is what we-are called' .upon to decide. The elucidation of that question cannot be aided by counting heads.
It is said that great benefits have resulted from the operation of such statutes, not alone in the District of Columbia but in the several States, where they have been iii force. A mass of reports, opinions of special observers and students of the subject, and the like, has been brought before us in support of this statement, all of which we have found interesting but only mildly persuasive. That the earnings of women now are greater than they were formerly and that conditions affecting women have become better in other respects may be conceded, but convincing indications of the logical relation of these desirable changes to the law in question are significantly lacking. They may be, and quite . probably are, due to other causes. We cannot close our eyes to the notorious fact that earnings everywhere in all occupations have greatly increased — not alone in States where the minimum wage law obtains but in the country generally — quite as much or more among men as among women and in occupations outside the reach of the law as in those governed by it. No real test of the economic value of the law can be had during periods of maximum employment, when general causes keep wages up to or above the minimum; that will 'come in periods of depression and struggle- for employment when the efficient will be employed at the minimum rate while the less capable may not be employed at all.
Finally, it may be said that if, in the interest of >the public welfare, the police power may be invoked to justify, the fixing óf a minimum wage, it may, whep-the public welfare is thought, to requir-e it, be invoked,-to justify a maximum wage. The power to fix high wages connotes, by like course of reasoning, the powep to fix low wages. If, in the face of the guaranties of the Fifth [561]*561Amendment, this form of legislation shall be legally justified, the field for the operation of the police power will have been widened to a great and dangerous degree. If, for example, in the opinion of future lawmakers; wages in the building trades shall become so high as to preclude people of ordinary means from building and owning homes, an authority which sustains the minimum wage will be invoked to support a maximum wage for building laborers and artisans, and the same argument which has been here -urged to strip the employer of his constitutional liberty of contract in one direction will be utilized to strip the employee of his constitutional liberty of contract in the opposite direction. A wrong decision does not end with itself: it is a precedent, and, with the swing of sentiment, its bad influence may run from one extremity of the arc to the other.
It has been said that legislation of the kind now under review is required in the interest of social justice, for whose ends freedom of contract may lawfully be subjected to restraint. The liberty of the individual to do as he pleases, even in innocent matters, is not absolute. It must frequently yield to the common good, and the line beyond which the power of interference may not be pressed is neither definite nor unalterable but may be made to move, within limits not well defined, with changing need and circumstance. Any attempt to fix a rigid boundary would be unwise as well as futile. But, nevertheless, there are limits to the power, and when these have been passed, it becomes the plain duty of the courts in the proper exercise of their authority to so declare. To sustain the individual freedom' of action contemplated by the Constitution, is not to strike down the common good but tó exalt it; for surely the good of society as a whole cannot be better served than by the preservation against arbitrary restraint of the liberties of its constituent members.
[562]*562It follows from what has been said that the act in question passes the limit prescribed by the Constitution, and, accordingly, the decrees of the court below are
Affirmed.
Mr. Justice Brandéis took no part in the consideration or decision of these cases.