delivered the opinion of the Court.

The.New State Ice Company, engaged in the business of manufacturing, selling and distributing ice under a license or permit duly issued by the Corporation Commission of Oklahoma, brought this suit against Liebmann in the federal district court for the western district of Oklahoma to enjoin him from manufacturing, selling and distributing ice within Oklahoma City without first having obtained a like license or permit from the commission. The license or permit is required by an act of the Oklahoma legislature, c. 147, Session Laws, 1925. That act declares that the manufacture, sale and distribution of ice is a public business; that no one shall be permitted to manufacture, sell or distribute ice within the state without -first having secured a license for that purpose from the commission; that whoever shall engage in such business without obtaining the license shall be guilty of a misdemeanor, punishable by fine not to exceed $25, each day’s violation constituting a separate offense, and that by general order of the, commission, a fine not to exceed $500 may be imposed for each violation.

Section 3 of the act provides:

“ That the Corporation Commission shall not issue license to any person, firm or corporation for the manufacture, sale and distribution of ice, or either of them, within this State, except upon a hearing had by said Commission at which said hearing, competent testimony and proof shall be presented showing the necessity for the manufacture, sale or distribution of ice, or either of them, *272at the point, community or place desired. If the facts proved at said hearing disclose that the facilities for the manufacture, sale and distribution of ice by some person, firm or corporation already licensed by said commission at said point, community or place, are sufficient to meet the public needs therein, the said Corporation Commission may refuse and deny the applicant [application] for said license. In addition to said authority, the said Commission shall have the right to take into consideration the responsibility, reliability, qualifications and capacity of the person, firm or corporation applying for said-license and of the person, firm or corporation already licensed in said place or community, as to afford all reasonable facilities, conveniences and services to the public and shall have the power and authority to require such facilities and services to be afforded the public; provided, that nothing herein shall operate to prevent the licensing of any person, firm or corporation now engaged in the manufacture, sale and distribution of ice, or either of them, in any town, city or community of -this State, whose license shall be granted and issued by said Commission upon application of such person, firm or corporation and payment of license fee.”

The portion of the section immediately in question here is .that which forbids the commission to issue a license to any applicant except upon proof of the necessity for a supply of ice at the place where it is sought to establish the business, and which authorizes a denial' of the application where the existing licensed facilities “ are sufficient to meet the public needs therein.” The district court dismissed the bill of complaint for want of equity, on the ground that the manufacture and sale of ice is a private business which may not be subjected to the foregoing regulation. 42 F. (2d) 913. The court of appeals affirmed. 52 F. (2d) 349.

*273. It must be conceded that all businesses are subject to some measure of public regulation. And that the business of manufacturing, selling or distributing ice, like that of the grocer, the dairyman, the butcher or the baker may be subjected to appropriate regulations in the interest of the public health cannot be doubted; but the question here is whether the business is so charged with a public use as to justify the particular restriction above stated. If this legislative restriction be within the constitutional power of the state legislature, it follows that the license or permit, issued to appellant, constitutes a franchise, to which a court of equity will afford protection against one who seeks to carry on the same business without obtaining from the commission a license or permit to do so. Frost v. Corporation Commission, 278 U. S. 515, 519-521. In that view, engagement in the business is a privilege to be exercised only in virtue of ,a public grant, and not a common right to be exercised independently (id.) by any competent person conformably to reasonable regulations equally applicable to all who choose to engage therein.

The Frost case is relied on here. That case dealt' with the business of operating a cotton gin. It was conceded that this was ,a business clothed with a public interest, and that the statute requiring a showing of public necessity as a condition precedent to the issue of a permit was valid. But the conditions which warranted the concession there are wholly wanting here. It long has been recognized that mills for the grinding of grain or performing similar services for all comers ,are devoted to a public use and subject to public control, whether they be operated by direct authority of the state or entirely upon individual initiative. At a very early period a majority of the states had adopted general acts authorizing the taking and flowage, in invitum, of lands for their erection and maintenance. In passing these acts, the attention of'the legislatures no *274doubt was directed principally to grist mills; but some of the acts, either in precise terms or in their application, were extended to other kinds of mills. Head v. Amoskeag Mfg. Co., 113 U. S. 9, 16-19; State v. Edwards, 86 Me. 102, 104-106; 29 Atl. 947. The mills were usually operated by the use of water power, but this method of operation has been said not to be essential. State v. Edwards, supra, at p. 106. It was open to the proprietor of a mill to maintain it as a private mill for grinding his own grain, and thus free from legislative control; but if the proprietor assumed to serve the general public he thereby dedicated his mill to the public use and subjected it to such législative control as was appropriate to that status. In such cases the mills were regarded as so necessary to the existence of the communities which they served as to justify the government in fostering and maintaining them, and imposing limitations upon their operation for the protection of the public. Id.

In Chickasha Cotton Oil Co. v. Cotton County Gin Co., 40 F. (2d) 846, three circuit judges passed upon the constitutionality of the Oklahoma cotton ginning act. Opinions were delivered seriatim, all to the effect, but for varying reasons, that the business of operating cotton gins in Oklahoma was clothed with a public interest. One of the judges thought that the rule in respect of grist mills should apply by analogy, on the ground of the similarity of service. The rule that mills whose services are open to all comers are clothed with a public interest was formulated in the light, and upon the basis, of historical usage, which had survived the limitations that otherwise might be imposed by the due process clause of the Fourteenth Amendment. While the cotton gin has no such background of ancient usage, and, as the opinion by Judge Phillips points out, there is always danger of our being led afield by relying over-much upon analogies, the analogy here is not without helpful significance.

*275In that connection we also may consider Clark v. Nash, 198 U. S. 361, and Strickley v. Highland Boy Mining Co., 200 U. S. 527, which dealt with the cognate question of what is a public use in respect of which the right of eminent domain may be exercised. The cases involved a statute of the State of Utah, which declared:

“ The cultivation and irrigation of the soil, the production and reduction of ores, are of vital necessity to the people of the State of Utah; are pursuits in which all are interested and from which all derive a benefit; and the use and application of the unappropriated waters of the natural streams and water courses of the State to the generation of electrical force or energy to be employed in industrial pursuits are of great public benefit and utility. So irrigation of land, the mining, milling, smelting or other reduction of ores, and such use and application of such waters for the generation of electrical power to be employed as aforesaid are hereby declared to be for the public use, and the right of eminent domain may be exercised in behalf thereof.” c. 95, §. 1, Laws of Utah, 1896.

In the Nash case, this court, applying that statute, sustained the condemnation of a right of way across the lands of one private owner for a ditch to convey water for the purpose of irrigating the lands of another private owner. The decision was rested explicitly upon the existence of conditions peculiar to the state. These conditions are epitomized in the legislative declaration above quoted. The court said (pp. 369-370) that its decision was not to be understood as approving the broad proposition that private property might be taken in all cases where the taking might promote the public interest and tend to develop the natural resources of the state, but, having reference to the conditions there appearing, “ that the use is a public one, although the taking of' the right of way is for the purpose simply of thereby obtaining the water for an individual, where it is absolutely necessary to *276enable him to make any use whatever of his land, and which will be valuable and fertile only if water can be obtained.”

This was followed in the Strickley case, where, mining being one of the chief industries of the state and its development peculiarly important for the public welfare, the condemnation of a right of way for an aerial bucket line across private lands, for the purpose of transporting ores from a- mine in private ownership, was upheld under the same statute.

These cases, though not strictly analogous, furnish persuasive ground for upholding the declaration of the Oklahoma legislature in respect of the public nature of cotton gins in that state. The production of cotton is the chief industry of the State of Oklahoma, and is of such paramount importance as to justify the assertion that the general welfare and prosperity of the state in a very large and real sense depend upon its maintenance. Cotton ginning is a process which must take place before the cotton is in a condition for the market. The cotton gin bears the same relation to the cotton grower that the old grist mill did to the grower of wheat. The individual grower of the raw product is generally financially unable to set up a plant for himself; but the service is a necessary one with which, ordinarily, he cannot afford to dispense. He is compelled, therefore, to resort for- such service to the establishment which operates in his locality. So dependent, generally, is he upon the neighborhood cotton gin that he faces the practical danger of being placed at the mercy of the operator in respect of exorbitant charges and arbitrary control. The relation between the growers of cotton, who constitute a very large proportion of the population, and those engaged in furnishing the service, is thus seen to be a peculiarly close one in respect of an industry of vital concern to the general public. These considerations render it not unreasonable *277to conclude that the business “ has been devoted to a public use and its use thereby, in effect, granted to the public.” Tyson & Bro. v. Banton, 273 U. S. 418, 434; Wolff Co. v. Industrial Court, 262 U. S. 522, 535, 538; same case, 267 U. S. 552, 563, et seq.

We have thus, with some particularity, discussed the circumstances which, so far as the State of Oklahoma is concerned, afford ground for sustaining the legislative pronouncement that the business of operating cotton gins is charged with a public use, in order to put them in contrast with the completely unlike circumstances which attend the business of manufacturing, selling and dis-. tributing ice. Here we áre dealing with an ordinary business, not with a paramount industry upon which the prosperity of the entire state in large measure depends. It is a business as essentially private in its nature as the business of the grocer, the dairyman, the butcher, the baker, the shoemaker, or the tailor, each of whom performs a service which, to a greater or less extent, the community is dependent upon and is interested in having maintained; but which bears no such relation to the public as to warrant its inclusion.in the category of businesses charged with a public use. It may be quite true that in Oklahoma ice is not only an article of prime necessity, but indispensable; but certainly not more so than food or clothing or the shelter of a home. And this court has definitely said that the production or sale of food or clothing cannot be subjected to legislative regulation on the basis of a public use; and that the same is true in respect of the business of renting houses and apartments, except as to temporary measures to tide over grave emergencies. See Tyson & Bro. v. Banton, supra, pp. 437-438, and cases cited.

It has been said that the manufacture of ice requires an expensive plant beyond the means of the average citizen, and thát since the use of ice is indispensable, patronage *278of the producer by the consumer is unavoidable. The same might, however, be said in respect of other articles clearly beyond the reach of a restriction like that here under review. But, for the moment conceding the materiality of the statement, it is not now true, whatever may have been the fact in the past. We know, since it is common knowledge, that today, to say nothing of other means, wherever electricity or gas is available (and one or the other is.available in practically every part of the country), anyone for a comparatively moderate outlay may have set up in his kitchen an appliance by means of which he may manufacture ice for himself. Under such circumstances it hardly will do to say that people generally are at the mercy of the manufacturer, seller and distributer of ice for ordinary needs. Moreover, the practical tendency of the restriction, as the trial court suggested in the present case, is to shut out new enterprises, and thus create and foster monopoly in the hands of existing establishments, against, rather than in aid of, the interest of the consuming public.

Plainly, a regulation which has the effect of denying or unreasonably curtailing the common right- to engage in a lawful private business, such as that under review, cannot be upheld consistently with the Fourteenth Amendment. Under that amendment, nothing is more clearly settled than that it is beyond the power of a state, “ under the guise of protecting the public, arbitrarily [to] interfere with private business or. prohibit lawful occupations or impose unreasonable and unnecessary restrictions upon them.” Burns Baking Co. v. Bryan, 264 U. S. 504, 513, and authorities cited; Liggett Co. v. Baldridge, 278 U. S. 105, 113.

Stated succinctly, a private corporation here seeks to prevent a competitor from entering the business of making and selling ice. It claims to be endowed with state authority to achieve this exclusion. There is no' question *279now before us of any regulation by the state to protect the consuming public either with respect to conditions of manufacture and distribution or. to insure purity of product or to prevent extortion. The control here asserted does not protect against monopoly, but tends to foster it. The aim is not to encourage competition, but to prevent it; not to regulate the business, but to preclude persons from engaging in it. There is no difference in principle between this case and the attempt of the dairyman under state authority to prevent another from keeping cows and selling milk on the ground that there are enough dairymen in the business; or to*prevent a shoemaker from making or selling shoes because shoemakers already in that occupation can make and sell all the shoes that are needed. We are not able to see anything peculiar in the business here in question which distinguishes it from ordinary manufacture and production. It is said to be recent; but it is the character of the business and not the date when it began that is determinative. It is not the case of a natural monopoly, or of an enterprise in its nature dependent upon the grant of public privileges. The particular requirement before us was evidently not imposed to prevent a practical monopoly of the business, since its tendency is quite to the contrary. Nor is-it a case of ■ the protection of natural resources. There is nothing in the product that we can perceive on which to rest a distinction, in respect of this attempted control, from other products in common use which enter into free competition, subject, of course, to reasonable regulations prescribed for the protection of the public and applied' with appropriate impartiality.

And it is plain that unreasonable or arbitrary interference or restrictions cannot be saved from the condemnation of that Amendment merely by calling them experimental. It is not necessary to challenge the authority of the states to indulge in experimental legislation; but *280it would be strange and unwarranted doctrine to hold that they may do so by enactments which transcend the limitations imposed upon them by the federal Constitution. The principle is imbedded in our constitutional system that there are certain essentials of liberty with which the state is not entitled to dispense in the interest of experiments. This principle has been applied by this court in many cases. Dorchy v. Kansas, 264 U. S. 286; Wolff Co. v. Industrial Court, 262 U. S. 522, 267 U. S. 552; Pierce v. Sisters, 268 U. S. 510; Nixon v. Herndon, 273 U. S. 536; Tumey v. Ohio, 273 U. S. 510; Manley v. Georgia, 279 U. S. 1; Washington v. Roberge, 278 U. S. 116; Chicago, St. P., M. & O. Ry. Co. v. Holmberg, 282 U. S. 162; Stromberg v. California, 283 U. S. 359; Near v. Minnesota, 283 U. S. 697. In. the case last .cited the theory of experimentation in censorship was not permitted to interfere with the fundamental doctrine of the-freedom of the press. The opportunity to apply one’s labor and skill in an ordinary occupation with proper regard' for all reasonable regulations is no less entitled to protection.

Decree affirmed.

dissenting.

Chapter 147 of the Session Laws of Oklahoma, 1925, declares that the manufacture of ice for sale and distribution is “ a public business ”; confers upon the Corporation Commission in respect to it the powers of regulation customarily exercised over public utilities; ,and -provides specifically for securing adequate service. The statute makes it a misdemeanor to engage in the business without a license from the Commission; directs that the license shall not issue except pursuant to a prescribed written application, after a formal hearing upon adequate notice *281both to the community to be served and to the general public, and a showing upon competent evidence, of the necessity “ at the place desired;” and it provides that the application may be denied, among other grounds, if “ the facts proved at said hearing disclose that the facilities for the manufacture, sale and distribution of ice by some person, firm or corporation already licensed by said Commission at said point, community or place are sufficient to meet the public needs therein.”

Under a license, so granted, the New State Ice Company is, and for some years has been, engaged in the manufacture, sale and distribution of ice at Oklahoma City, and has invested in that business 1500,000. While it was so engaged, Liebmann, without having obtained or applied for a license, purchased a parcel of land in that city and commenced the construction thereon of an ice plant for the purpose of entering the business in competition with the plaintiff. To enjoin him from doing so this suit was brought by the Ice Company. Compare Frost v. Corporation Commission, 278 U. S. 515. Liebmann contends that the manufacture of ice for sale and distribution is not a public business; that it is a private business and, indeed, a common calling; that the right to engage in a common calling is one of the fundamental liberties guaranteed by the due process clause; and that to make his right to engage in that calling dependent upon a finding of public necessity deprives him of liberty and property in violation of the Fourteenth Amendment. Upon full hearing the District Court sustained that contention and dismissed the bill. 42 F. (2d) 913. Its decree was affirmed by the Circuit Court of Appeals. 52 F. (2d) 349. The case is here on appeal. In my opinion, the judgment should be reversed.

First. The Oklahoma statute makes entry into the business of manufacturing ice for sale and distribution dependent, in effect, upon a certificate of public convenience *282and necessity. Such a certificate was unknown to the common law. It is a creature of the machine age, in which plants have displaced tools and businesses are substituted for trades. The purpose of requiring it is to promote the public interest by preventing waste. Particularly in those businesses in which interest and depreciation charges on plant constitute a large element in the cost of production, experience has taught that the financial burdens incident to unnecessary duplication of facilities are likely to bring high rates and poor service.1 There, cost is usually dependent, among other things, upon volume; and division of possible patronage among competing concerns may so raise the unit cost of operation as to make it impossible to provide adequate service at reasonable rates. The introduction in the United States of the certificate of public convenience and necessity marked the growing conviction that under certain circumstances free competition might be harmful to the community and that, when it was so, absolute freedom to enter the business of one’s choice should be denied.

Long before the enactment of the Oklahoma statute here challenged a like requirement had become common in the United States in some lines of business. The certificate -was required first for railroads; then for street railways; then for other public utilities whose operation is dependent upon the grant of some special privilege.2 *283Latterly, the requirement has been widely extended to common carriers by motor vehicle which use the highways, but which, unlike street railways and electric light' companies, are not dependent upon the grant of any special privilege.3 In Oklahoma the certificate was required, as early as 1915, for cotton gins — a business then declared a public one, and, like the business of manufacturing ice,, conducted wholly upon private property. Sess. Laws, 1915, c. 176, § 3. See Frost v. Corporation Commission, 278 U. S. 515, 517. As applied to public. utilities, the validity under the Fourteenth Amendment of the requirement of the certificate has never been successfully questioned.

Second. Oklahoma declared the business of manufacturing ice for sale and distribution a “ public business; ” that is, a public utility. So far as appears, it was the first State to do so.4 Of course, a legislature cannot by-*284mere legislative fiat convert a business into a public utility. Producers Transportation Co. v. Railroad Commission, 251 U. S. 228, 230. But the conception of a public utility is not static.5 The welfare of the community may require that the business of supplying ice be made a public utility, as well as the business of supplying water or any other necessary commodity or service. If the business is, or can be made, a public utility, it must be possible to make the issue of a certificate a prerequisite to engaging in it.

Whether the local conditions are such as to justify converting a private business into a public one is a matter primarily for the determination of the state, legislature. Its determination is subject to judicial review; but the usual presumption of validity attends the enactment.6 *285The action of the State must be held valid unless clearly arbitrary, capricious or unreasonable. “ The - legislature being familiar with local conditions is, primarily, the judge of the necessity of such enactments. The mere fact that a court may differ with the legislature in its views of public policy, or that judges may hold views inconsistent with the propriety of the legislation in question, affords no ground for judicial interference, . . .” McLean v. Arkansas, 211 U. S. 539, 547. Whether the grievances are real or fancied, whether the remedies are wise or foolish, are not matters about which the Court may concern itself.7 “ Our present duty is to pass. upon the statute before us, and if it has been enacted upon a belief of evils that is not arbitrary we cannot measure their extent against the estimate of the legislature.” Tanner v. Little, 240 U. S. 369, 385. A decision that the legislature’s belief of evils was arbitrary, capricious and unreasonable may not be made without enquiry into the facts with reference to which it acted.

Third. Liebmann challenges the statute — not an order of the Corporation Commission. If he had applied for a license and been denied one, we should have been obliged to enquire whether the evidence introduced before *286the Commission justified it in. refusing permission to establish an additional ice plant in Oklahoma City. As he did not apply but challenges the statute itself, our enquiry is of an entirely different nature. Liebmann Tests his defense upon the broad claim that the Federal Constitution gives him the right to enter' the business of manufacturing ice for sale even if his doing so be found by the properly constituted, authority to be inconsistent with the public welfare. He claims that, whatever the local conditions may demand, to confer upon the Commission power to deny that right is an unreasonable, arbitrary and capricious restraint upon his liberty.

The function of the Court is primarily to determine whether the conditions in Oklahoma are such that the legislature could not reasonably conclude (1) that the public welfare required. treating the manufacture of ice for sale and distribution as a “public business”; and (2) that in order to ensure to the inhabitants of some communities an adequate supply of ice at reasonable rates it was necessary to give the Commission power to exclude the establishment of an additional ice plant in places where the community was already well served. Unless the Coürt can say that the Federal Constitution confers an absolute right to engage anywhere in the business of manufacturing ice for sale, it cannot properly decide that the legislators acted unreasonably without first ascertaining what was the experience of Oklahoma in respect to the ice business. The relevant facts appear, in part, of record. Others are matters of common knowledge to those familiar with the ice business. Compare Muller v. Oregon, 208 U. S. 412, 419, 420. They show the. actual conditions, or the beliefs, on which the legislators acted. In considering these matters we do not, in a strict senseitake judicial notice of them as embodying statements of' uncontrovertible facts. Our function is only to determine the reasonableness of the legislature’s belief in the existence" of evils and in the effectiveness of the remedy *287provided. In performing this function we have no occasion to consider whether all the statements of fact which may be the basis of the-prevailing belief are well-founded; and we have, of course, no right to weigh conflicting evidence.

(A) In Oklahoma a regular supply of ice may reasonably be considered a necessary of life, comparable to that of water, gas and electricity. The climate, which heightens the need of ice for comfortable and wholesome living, precludes resort to the natural product.8 There, as elsewhere, the development of the manufactured ice industry in recent years 9 has. been attended by deep-seated alterations in the economic structure and by radical changes in habits of popular thought and living. Ice has come to be regarded as a household, necessity, indispensable to the preservation, of' food and so to economical household management and the maintenance of health.10. Its.crm*288mercial uses are extensive. In urban communities, they absorb a large proportion of the total amount of ice manufactured for sale.11 The transportation, storage and distribution of a great - part of the nation’s food supply is dependent upon a continuous, and dependable supply of ice.12 It appears from the record that in certain parts Of Oklahoma a large trade in dairy and other products has *289been built up as a result of rulings of the Corporation Commission under the Act of 1925, compelling licensed manufacturers to serve agricultural communities;13 and that this trade would be destroyed if the supply of ice. were withdrawn.14 .We cannot say that the legislature of Oklahoma acted arbitrarily in declaring that ice is an ■article of primary necessity, in industry and agriculture as well as in the household, partaking of the fundamental character of electricity, gas, water, transportation and' communication.

Nor can the Court properly take judicial notice that, in Oklahoma, the means of manufacturing ice,for private use are within the reach of all persons who are dependent upon it. Certainly it has not been so. In 1925 domestic mechanical refrigeration had scarcely emerged from the experimental stage.15 Since that time, the production and consumption of ice manufactured, for sale, far from *290diminishing, has steadily increased.16 In Oklahoma the mechanical household refrigerator is still an article of relative luxury.17 Legislation essential to the protection of individuals of limited or no means is not invalidated by the circumstance that other individuals are financially able to protect themselves.. The businesses of power companies and of common carriers by street railway, steam railroad or motor vehicle fall within the field of public control, although it is possible, for a relatively modest outlay, to install individual power plants, or to purchase *291motor vehicles for private carriage of passengers or goods. The question whether in Oklahoma the means of securing refrigeration otherwise than by ice manufactured for sale and distribution has become so general as to destroy popular dependence upon ice plants is one peculiarly appropriate for the determination of its legislature and peculiarly inappropriate for determination by this Court, which cannot have knowledge of all the relevant facts. ,

The business of supplying ice is not only a necessity, like that of supplying food or clothing or shelter, but the legislature could also consider that it is one which lends itself peculiarly to monopoly.18 Characteristically the business is conducted in local plants with a market narrowly limited in area,19 and this for the reason that ice *292manufactured at a distance cannot effectively compete with a plant on the ground.20 In small towns and rural communities21 the duplication of plants, and in larger communities the duplication of delivery service,22 is wasteful and ultimately burdensome to consumers. At the same time the relative ease and cheapness with which an ice plant may be constructed exposes the industry to destructive and frequently ruinous competition. Competition in the industry • tends to be destructive because ice plants have a determinate capacity, and inflexibledixed charges and operating costs, and because in a' market of limited area the volume of sales is not readily expanded. Thus, the erection of a new plant in a locality already adequately served often causes managers to go to extremes in cutting prices in order to secure business. Trade journals and reports of association meetings of ice manufacturers bear ample witness to the hostility of the industry to such corn-*293petition, and to its unremitting efforts, through trade associations, informal agreements, combination of delivery-systems, and in particular through the consolidation of plants, to protect markets and prices against competition of any character.23

That these forces were operative in Oklahoma prior to the passage of the Act under review, is apparent from the record. Thus, it was testified that in only six or seven localities in the State containing, in the aggregate, not more than 235,000 of the total population of approximately 2,000,000, was there “ a semblance of competition ”;24 and that even in those localities the prices of ice were ordinarily uniform. The balance of the population was, and still is, served by companies enjoying complete monopoly. Compare Munn v. Illinois, 94 U. S. 113, 131, 132; Sinking Fund Cases, 99 U. S. 700, 747; Wabash, St. L. & P. Ry. Co. v. Illinois, 118 U. S. 557, 569; Spring Valley Water Works v. Schottler, 110 U. S. 347, 354; Budd v. New York, 143 U. S. 517, 545; Wolff Co. v. Industrial Court, 262 U. S. 522, 528. Where there was competition, it often resulted to. the disadvantage rather *294than the advantage of the public, both in respect to prices and to service. Some communities were without ice altogether, and the State was without means of assuring their supply. There is abundant evidence of widespread dis-\ satisfaction with ice service prior to the Act of 1925,25 and of material improvement in the situation subse- . quently. It is stipulated in the record that the ice industry as a whole in Oklahoma has acquiesced in and accepted the Act and the status which it creates.

(B) The statute under review rests not only upon the facts just detailed but upon a long period of experience in more limited regulation dating back to the first year of Oklahoma’s statehood. For 17 years prior to the passage of the Act of 1925, the Corporation Commission under § 13 of the Act of. June 10, 1908, had exercised jurisdiction oyer the rates, practices and service of ice plants, its action in each case, however, being predicated upon a finding that the company complained of enjoyed a “virtual monopoly” of the ice business in the community which it served.26 The jurisdiction thus exer*295cised was upheld by the Supreme. Court of the State in Oklahoma Light & Power Co. v. Corporation Commission, 96 Okla. 19; 220 Pac. 54. The court said, at p. 24:

“ The manufacture, sale, and distribution of ice in many respects closely resemble the sale and'distribution of gas as fuel, or electric current, and in many communities the same company that manufactures, sells, and distributes electric current is the only concern that manufactures,. sells,.and distributes ice, and by reason of the nature and extent of the ice business it is impracticable in that community to interest any other concern in such business. In this situation, the distributor of such a necessity as ice should not be permitted by reason of the impracticability of any one else engaging in the business to charge unreasonable prices, and if such an abuse is persisted in, the'regulatory power of the State should be invoked to protect the public.” See also Consumers Light & Power Co. v. Phipps, 120 Okla. 223; 251 Pac. 63.

By formal orders, the Commission repeatedly fixed or approved prices to be charged in particular communities;27 required ice to be sold without discrimination28 *296and to be distributed as equitably as possible to the extent of the capacity of the plant;29 forbade short weights and ordered scales to be carried on delivery wagons and ice to be weighed upon the customer’s request;30 and undertook to compel sanitary practices in the manufacture of ice31 and courteous service of patrons.32 Many of these regulations, other than those fixing prices, were embodied in a general order to all ice companies, issued July 15, 1921, and are still in effect.33 Informally, the Commis*297sion adjusted a much greater volume of complaints of a similar nature.34 It appears from the record that for some years prior to the Act of 1925 one day of each week was reserved by the Commission to hear complaints relative to the ice business.

As early as 1911, the Commission in its annual report to the Governor, had recommended legislation more clearly delineating its powers in this field:

“ There should be a law passed putting the regulation of ice plants under the jurisdiction of the Commission. The Commission is now assuming this jurisdiction under an Act passed by the Legislature known as the anti-trust law. A specific law upon this subject would obviate any question of jurisdiction.” 35

This recommendation was several times repeated, in terms revealing the extent and character of public complaint against the practices of ice companies.36

*298The enactment of the so-called Ice Act in. 1925 enlarged the existing jurisdiction of the Corporation Commission by removing the requirement of a finding of virtual monopoly in each particular case, compare Budd v. New York, 143 U. S. 517, 545, with Brass v. Stoeser, 153 U. S. 391, 402, 403; by conferring the same authority to compel adequate service as in the case of other public utilities; and by committing to the Commission the function of issuing licenses equivalent to a certificate of public convenience and necessity. With the exception of the granting and denying of such licenses and the exertion of wider control over service, the regulatory activity of the Commission in respect to ice plants has not changed in character since 1925. It appears to have diminished somewhat in volume.37

*299In 1916, the. Commission urged, in its report to the Governor, that all public utilities under its jurisdiction be required to secure from the Commission “what is known as a ‘certificate of.public convenience and necessity ’ before the duplication of facilities.”

“ This would prevent ruinous competition resulting in the driving out of business of small though' competent public service utilities by more powerful corporations, and often consequent demoralization of service, or the requiring of the public to patronize two utilities in a community where one would be adequate.” 38

Up to that time a certificate of public convenience and necessity to engage in the business had been applied only to cotton gins. Okla. Sess. Laws, 1915, c. 176, § 3: In 1917 a certificate from the Commission was declared prerequisite to the construction of new telephone or telegraph lines.39 In 1923 it was required for the operation of motor carriers.40 In 1925, the year in which the Ice Act was passed, the requirement was extended also to power, heat, light, gas, electric or water companies pro*300posing to do business in any locality already possessing one such utility.41

Fourth. Can it be said in the light of these facts that it was not an appropriate exercise of legislative discretion to authorize the Commission to deny a license to enter the business in localities where necessity for another plant did not exist? The need of some remedy for the evil of destructive competition, where competition existed, had been and was widely felt. Where competition did not exist, the propriety of public regulation had been proven. Many communities were not supplied with ice at all. The particular remedy adopted was not enacted hastily. The statute was based upon a long-established state policy recognizing the public importance of the ice business, and upon 17 years’ legislative and administrative experience in the regulation of it. The advisability of treating the ice business as a public utility and of applying to it the certificate of convenience and necessity had been under consideration for many years. Similar legislation had been enacted in Oklahoma under similar circumstances with respect to other public services. The measure bore a substantial relation to the evils found to exist. Under these circumstances, to hold the Act void as being unreasonable, would, in my opinion involve the exercise not of the function of judicial review, but the function of a super-legislature. If the Act is to be stricken down, it must be on the ground that the Federal Constitution guarantees to the individual the absolute right to enter the ice business, however detrimental the exercise o(f that right may be to the public welfare. Such,' indeed, appears to be the contention made.

*301Fifth. The claim, is that manufacturing ice for sale and distribution is a business inherently private, and, in effect, that no state of facts can justify denial of the right to engage in it. To supply one’s self with water, electricity, gas, ice or any other article, is inherently a matter of private concern. So also may be the business of supplying the same articles to others for compensation. But the business of supplying to others, for compensation, any article or service whatsoever may become a matter of public concern. Whether it is, or is not, depends upon the conditions existing in the community affected.42 If it is a matter of public concern, it may be regulated, whatever the business. The public’s concern may be limited to a single feature of the business, so that the needed protection can be secured by a relatively slight degree of regulation. Such is the concern over possible incompetence, which dictates the licensing of dentists, Dent v. West Virginia, 129 U. S. 114, 122; Douglas v. Noble, 261 U. S. 165, 170; or the concern over possible dishonesty, which led to the licensing of auctioneers or hawkers, Baccus v. Louisiana, 232 U. S. 334, 338. On the other hand, the public’s concern about a particular business may be so pervasive and varied as to require constant detailed supervision and a very high degree of regulation. Where this is true, it is common to speak of the business as being a “ public ” one, although it- is privately owned. It is to such businesses that the designation “ public utility ” is commonly applied; or they are spoken.of as “ affected with a public interest.” German Alliance Ins. Co. v. Lewis, 233 U. S. 389, 408.

A regulation valid for one kind of business may, of course, be invalid for another; since the reasonableness' *302of every regulation is dependent upon the relevant facts. But so far as concerns the power to regulate, there is no difference in essence, between a business called private and one called a public utility or said to be “ affected with a public interest.” Whatever the nature of the business, whatever the scope or character of the regulation applied, the source of the power invoked is the same. And likewise the constitutional limitation upon that power. ■ The source is the police power. The limitation is that set by the due process clause, which, as construed, requires- that the regulation shall be not unreasonable, arbitrary or capricious; and that the means of regulation selected shall have a real or substantial relation to the object sought to be obtained. The notion of a distinct, category of business “ affected with a public interest,” employing property “ devoted to a public use,” rests upon historical error. The consequences which it is sought to draw from those phrases are belied by the meaning in which they were first used centuries ago,43 and by the decision of this Court, in Munn v. Illinois, 94 U. S. 113, which first introduced them into the law of the Constitution.44 In my opinion, the true principle is that the *303State’s power extends to every regulation of any business reasonably required and appropriate for the public protection. I find in the due process clause no other limitation upon the character or the scope of regulation permissible.

Sixth. It is urged specifically that manufacturing ice for sale and- distribution is a common calling; and that the right to engage in a common calling is one of the fundamental liberties guaranteed by the due process clause. To think of the ice-manufacturing business as a common calling is difficult; so recent is it in origin and so peculiar in character. Moreover, the Constitution does not require that every calling which has been common shall ever remain so. The liberty to engage in a common calling, like other liberties, may be limited in the exercise of the police power. The slaughtering of cattle had been a common calling in New Orleans before the monopoly sustained in Slaughter-House Cases, 16 Wall. 36, was created by the legislature. Prior to the Eighteenth Amendment selling liquor was a common calling, but this Court held it to be consistent with the due process clause for a State to abolish the calling, Bartemeyer v. Iowa, 18 Wall. 129; Mugler v. Kansas, 123 U. S. 623, or to establish a system limiting the number of licenses, Crowley v. Christensen, 137 U. S. 86. Every citizen has the right to navigate a river or lake, and may even carry others thereon for hire. But the ferry privilege may be made exclusive in order that the patronage may be sufficient to justify maintaining the ferry service, Conway v. Taylor’s Executor, 1 Black 603, 633, 634.

*3041 It is settled that the police power commonly invoked •in aid of health, safety and morals, extends equally to the promotion of the public welfare.45- The cases just cited show that, while, ordinarily, free competition in the com-, mon callings has been encouraged, the public welfare may at other times demand that monopolies be created. Upon this principle is based our whole modern practice of public utility regulation. It is no objection to the validity of the statute here assailed that it fosters monopoly. That, indeed, is its design. The certificate of public convenience and invention is a device — a recent social-economic invention — thrqugh which the monopoly is kept under effective control by vesting in a commission the power to terminate it whenever that course is required in the public interest. To grant any monopoly to any person as a ' favor is forbidden even if terminable. But where, as ['here, there is reasonable ground for the legislative con- : elusion that in order to secure a necessary service at ij reasonable rates, it may be necessary to curtail the right Jito enter the calling, it is, in my opinion,-consistent with the due process clause to do so, whatever the nature of the business. The existence of such power in the legislature seems indispensable in our ever-changing society. .

It is settled by unanimous decisions of this Court, that the due process clause does not prevent a State or city from engaging in the business of supplying its inhabitants with articles in general use, when it is believed that they *305cannot be secured at reasonable prices from the private dealers. Thus, a city may, if the local law permits, buy and sell at retail coal and wood, Jones v. Portland, 245 U. S. 217; or gasoline, Standard Oil Co. v. Lincoln, 275 U. S. 504. And a State may, if permitted by its own Constitution, build and operate warehouses, "elevators, packinghouses, flour mills or other factories, Green v. Frazier, 253 U. S. 233. As States may engage in a business, because it is a public purpose to assure to their inhabitants an adequate supply of necessary articles, may they not achieve this public purpose, as Oklahoma has done, by exercising the lesser power of preventing single individuals from wantonly engaging in the business and thereby making impossible a dependable private source of supply? As a State so entering upon a business may exert the taxing' power all individual dealers may be driven from the calling by the unequal competition. If States are denied the power to prevent the harmful entry of a few individuals’into a business, they may thus, in effect, close it-altogether to private enterprise.

Seventh. The economic emergencies of the past were incidents of scarcity. In those days it was preeminently the common callings that were the subjects of regulation. The danger then threatening was excessive prices. To prevent what was deemed extortion, the English Parliament fixed the prices of commodities and of services from time to time during the four centuries preceding the Declaration of Independence.46 Like legislation was en*306acted in the Colonies; and in the States, after the Revolution.47 When .the first due process clause was written into the Federal Constitution, the price of bread was being fixed by statute in at least two of the States, and this practice continued long thereafter.48 Dwelling houses when occupied by the owner are preeminently private property. From the foundation of our Government those who wished to lease residential property had been free to charge to tenants such rentals as they pleased. But for years after the World War had ended, the scarcity of dwellings in the City of New York was such that the State’s legislative power was invoked to ensure reasonable rentals. The constitutionality of the statute was sustained by this Court. Marcus Brown Holding Co. v. Feldman, 256 U. S. 170. Similar legislation of Congress for the City of Washington was also upheld. Block v. Hirsh, 256 U. S. 135.

Eighth. The people of the United States are now confronted with an emergency more serious 'than war. Misc.y is wide-spread, in a time, not of scarcity, but of over-abundance. The long-continued depression has brought unprecedented unemployment, a catastrophic fall in commodity prices and a volume of economic losses which threatens our financial institutions.49 Some people *307believe that the existing conditions threaten even the stability of the capitalistic system.50 Economists are searching for the causes of this disorder and are reexamining the bases of our industrial structure. Business men are seeking possible remedies. Most of them realize that failure to distribute widely the profits of industry has been a prime cause of our present plight. But rightly or wrongly, many ■ persons think that one of the major contributing causes has been unbridled competition.51 Increasingly, doubt is expressed whether it is economically wise, or morally right, that men should be permitted to *308add to the producing facilities' of an industry which is already suffering from over-capacity. In justification of that doubt, men point to the excess-capacity of our productive facilities' resulting from their vast expansion without corresponding increase in the consumptive capacity of the people. They assert that through improved methods of manufacture, made possible by advances in science and invention and vast accumulation of capital, our industries had become capable of producing from thirty to one hundred per cent, more than was consumed even in days of vaunted prosperity; and that the present capacity will, for a long time, exceed the needs of business.52 All agree that irregularity in employment — the greatest of our evils — cannot be overcome unless production and consumption are more nearly balanced. Many insist there must be some form of economic control. There are plans for proration. There? are many proposals for stabilization.53 And some thoughtful men ' *309of wide business experience insist that all projects for stabilization and proration must prove futile unless, in some wáy, the equivalent of the certificate of public convenience arid necessity is made a prerequisite to embarking new capital in an industry in which the capacity already exceeds the production schedules.54

Whether that view is sound nobody knows. The objections to the proposal are obvious and grave. The remedy might bring evils worse than the present disease.. The *310obstacles to success seem insuperable.55 The economic and social sciences are largely uncharted seas. We have been none too successful- in the modest essays in economic control already entered upon. The new proposal involves a vast extension of the area of control. Merely to acquire the knowledge essential ás a basis for the exercise of this multitude of judgments would be a formidable task; and each of the thousands of these judgments would call for some measure of prophecy. Even more serious are the obstacles to success inherent in the demands which execution of the project would make upon human intelligence and upon the character of men. Man is weak and his judgment is at best fallible.

Yet the advances in the exact sciences and the achievements in invention remind us that the seemingly impossible sometimes happens. There are many men now living who were in the habit of using the age-old expression: “It-is as impossible as flying.” The discoveries in physical science, the triumphs in invention, attest the value of the process of trial and error. In large measure, these advances have been due.to. experimentation. In those fields experimentation has, for two centuries, been not only free but encouraged. Some people assert that our present plight is due, in part, to the limitations set *311by courts upon experimentation in the fields of social and economic science; and to the discouragement to which proposals for betterment there have been subjected otherwise.. There must be power in the States and the Nation to remould, through experimentation, our economic practices and institutions to meet changing social and economic needs. I cannot believe that the framers of the-Fourteenth Amendment, or the States which ratified it, intended to deprive us of the power to correct the evils of technological unemployment and excess productive ca.pacity which have attended progress in the useful arts.56

To stay experimentation in things social and economic is a grave responsibility. Denial of the right to experiment may be fraught with serious consequences to the Nation. • It is one of the happy incidents of the federal system that a single courageous State may, if its citizens choose, serve as a laboratory; and try novel social and economic experiments without risk to the rest of the country; This Court has the power to prevent ah experiment.57 We may strike down the statute which embodies it on the ground that, in our opinion, the measure is arbitrary, capricious or unreasonable. We have power to do this, because the due process clause has been held by the Court applicable to matters of substantive law as well as to matters of procedure. But in the exercise of this high power, we must be ever on our guard, lest we erect our prejudices into legal principles. If we would guide by the light of reason, we must let our minds be bold.