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is clearly pointed out in National Cotton Oil Co. v. Texas, 197 U. S. 115, and Shawnee Compress Co. v. Anderson, 209 U. S. 423; and, indeed, will be found to be illustrated in various aspects by the decisions of this court which have been concerned with the enforcement of the act we are now considering.

Without going into detail and but very briefly surveying the whole field, it may be with accuracy said that the dread of enhancement of prices and of other wrongs which it was thought would flow from the undue limitation on competitive conditions caused by contracts or other acts of individuals or corporations, led, as a matter of public policy, to the prohibition or treating as illegal all contracts or acts which were unreasonably restrictive of competitive conditions, either from the nature or character of the contract or act or where the surrounding circumstances were such as to justify the conclusion that they had not been entered into or performed with the legitimate purpose of reasonably forwarding personal interest and developing trade, but on the contrary were of such a character as to give rise to the inference or presumption that they had been entered into or done with the intent to do wrong to the general public and to limit the right of individuals, thus restraining the free flow of commerce and tending to bring about the evils, such as enhancement of prices, which were considered to be against public policy. It is equally true to say that the survey of the legislation in this country on this subject from the beginning will show, depending as it did upon the economic conceptions which obtained at the time when the legislation was adopted or judicial decision was rendered, that contracts or acts were at one time deemed to be of such a character as to justify the inference of wrongful intent which were at another period thought not to be [59] of that character. But this again, as we have seen, simply followed the line of development of the law of England.

Let us consider the language of the first and second sections, guided by the principle that where words are employed in a statute which had at the time a well-known meaning at common law or in the law of this country they are presumed

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to have been used in that sense unless the context compels to the contrary."

As to the first section, the words to be interpreted are:

"Every contract, combination in the form of trust or otherwise, or conspiracy in restraint of trade or commerce * is hereby

declared to be illegal."

As there is no room for dispute that the statute was intended to formulate a rule for the regulation of interstate and foreign commerce, the question is what was the rule which it adopted?

In view of the common law and the law in this country as to restraint of trade, which we have reviewed, and the illuminating effect which that history must have under the rule to which we have referred, we think it results:

(a) That the context manifests that the statute was drawn in the light of the existing practical conception of the law of restraint of trade, because it groups as within that class, not only contracts which were in restraint of trade in the subjective sense, but all contracts or acts which theoretically were attempts to monopolize, yet which in practice had come to be considered as in restraint of trade in a broad sense.

(b) That in view of the many new forms of contracts and combinations which were being evolved from existing economic conditions, it was deemed essential by an allembracing enumeration to make sure that no form of contract or combination by which an undue restraint of [60] interstate or foreign commerce was brought about could save such restraint from condemnation. The statute under this view evidenced the intent not to restrain the right to make and enforce contracts, whether resulting from combination or otherwise, which did not unduly restrain interstate or foreign commerce, but to protect that commerce from being restrained by methods, whether old or new, which would constitute an interference that is an undue restraint.

Swearingen v. United States, 161 U. S. 446; United States v. Wong Kim Ark, 169 U. S. 649; Keck v. United States, 172 U. S. 446; Kepner v. United States, 195 U. S. 100, 126.

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(c) And as the contracts or acts embraced in the provision were not expressly defined, since the enumeration addressed itself simply to classes of acts, those classes being broad enough to embrace every conceivable contract or combination which could be made concerning trade or commerce or the subjects of such commerce, and thus caused any act done by any of the enumerated methods anywhere in the whole field of human activity to be illegal if in restraint of trade, it inevitably follows that the provision necessarily called for the exercise of judgment which required that some standard should be resorted to for the purpose of determining whether the prohibitions contained in the statute had or had not in any given case been violated. Thus not specifying but indubitably contemplating and requiring a standard, it follows that it was intended that the standard of reason which had been applied at the common law and in this country in dealing with subjects of the character embraced by the statute, was intended to be the measure used for the purpose of determining whether in a given case a particular act had or had not brought about the wrong against which the statute provided.

And a consideration of the text of the second section serves to establish that it was intended to supplement the first and to make sure that by no possible guise could the public policy embodied in the first section be frustrated or evaded. The prohibitions of the second embrace

[61] "every person who shall monopolize, or attempt to monopolize, or combine or conspire with any other person or persons, to monopolize any part of the trade or commerce among the several states, or with foreign nations,

By reference to the terms of § 8 it is certain that the word person clearly implies a corporation as well as an individual. The commerce referred to by the words "any part" construed in the light of the manifest purpose of the statute has both a geographical and a distributive significance, that is it includes any portion of the United States and any one of the classes of things forming a part of interstate or foreign commerce.

Undoubtedly, the words "to monopolize" and "monopolize" as used in the section reach every act bringing about

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the prohibited results. The ambiguity, if any, is involved in determining what is intended by monopolize. But this ambiguity is readily dispelled in the light of the previous history of the law of restraint of trade to which we have referred and the indication which it gives of the practical evolution by which monopoly and the acts which produce the same result as monopoly, that is, an undue restraint of the course of trade, all came to be spoken of as, and to be indeed synonymous with, restraint of trade. In other words, having by the first section forbidden all means of monopolizing trade, that is, unduly restraining it by means of every contract, combination, etc., the second section seeks, if possible, to make the prohibitions of the act all the more complete and perfect by embracing all attempts to reach the end prohibited by the first section, that is, restraints of trade, by any attempt to monopolize, or monopolization thereof, even although the acts by which such results are attempted to be brought about or are brought about be not embraced within the general enumeration of the first section. And, of course, when the second section is thus harmonized with and made as it [62] was intended to be the complement of the first, it becomes obvious that the criteria to be resorted to in any given case for the purpose of ascertaining whether violations of the section have been committed, is the rule of reason guided by the established law and by the plain duty to enforce the prohibitions of the act and thus the public policy which its restrictions were obviously enacted to subserve. And it is worthy of observation, as we have previously remarked concerning the common law, that although the statute by the comprehensiveness of the enumerations embodied in both the first and second sections makes it certain that its purpose was to prevent undue restraints of every kind or nature, nevertheless by the omission of any direct prohibition against monopoly in the concrete it indicates a consciousness that the freedom of the individual right to contract when not unduly or improperly exercised was the most efficient means for the prevention of monopoly, since the operation of the centrifugal and centripetal forces resulting from the right to freely contract was the means by which monopoly would be inevitably prevented

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if no extraneous or sovereign power imposed it and no right to make unlawful contracts having a monopolistic tendency were permitted. In other words that freedom to contract was the essence of freedom from undue restraint on the right to contract.

Clear as it seems to us is the meaning of the provisions of the statute in the light of the review which we have made, nevertheless before definitively applying that meaning it behooves us to consider the contentions urged on one side or the other concerning the meaning of the statute, which, if maintained, would give to it, in some aspects a much wider and in every view at least a somewhat different significance. And to do this brings us to the second question which, at the outset, we have stated it was our purpose to consider and dispose of.

[63] Second. The contentions of the parties as to the meaning of the statute and the decisions of this court relied upon concerning those contentions.

In substance, the propositions urged by the Government are reducible to this: That the language of the statute embraces every contract, combination, etc., in restraint of trade, and hence its text leaves no room for the exercise of judgment, but simply imposes the plain duty of applying its prohibitions to every case within its literal language. The error involved lies in assuming the matter to be decided. This is true because as the acts which may come under the classes stated in the first section and the restraint of trade to which that section applies are not specifically enumerated or defined, it is obvious that judgment must in every case be called into play in order to determine whether a particular act is embraced within the statutory classes, and whether if the act is within such classes its nature or effect causes it to be a restraint of trade within the intendment of the act. To hold to the contrary would require the conclusion either that every contract, act or combination of any kind or nature, whether it operated a restraint on trade or not, was within the statute, and thus the statute would be destructive of all right to contract or agree or combine in any respect whatever as to subjects embraced in interstate trade or commerce, or if this conclusion were not reached, then the contention