In Appalachian Coals, Inc. v. United States, 288 U.S. 344, 359, 53 S.Ct. 471, 474, 77 L.Ed. 825 (1933), the court said: "The purpose of the Sherman Anti-Trust Act is to prevent undue restraints of interstate commerce, to maintain its appropriate freedom in the public interest, to afford protection from the subversive or coercive influences of monopolistic endeavor. As a charter of freedom, the act has a generality and adaptability comparable to that found to be desirable in constitutional provisions. It does not go into detailed definitions which might either work injury to legitimate enterprise or through particularization defeat its purposes by providing loopholes for escape. The restrictions the act imposes are not mechanical or artificial. Its general phrases, interpreted to attain its fundamental objects, set up the essential standard of reasonableness. They call for vigilance in the detection and frustration of all efforts unduly to restrain the free course of interstate commerce, but they do not seek to establish a mere delusive liberty either by making impossible the normal and fair expansion of that commerce or the adoption of reasonable measures to protect it from injurious and destructive practices and to promote competition upon a sound basis. The decisions establish, said this Court in Nash v. United States, 229 U.S. 373, 376, 33 S.Ct. 780, 781, 57 L.Ed. 1232, `that only such contracts and combinations are within the act as, by reason of intent or the inherent nature of the contemplated acts, prejudice the public interests by unduly restricting competition or unduly obstructing the course of trade.'"