The largest element of cost in most economic production is that of labor. It is for the interest of employers to pay as little as possible, and for the interest of employees to obtain as large pay as posible. These objects can be promoted, if the law permits it, by agreements of employers or employees with those of their own class, not to employ or not to work except on specified advantageous terms. There has been much litigation involving the legality of combinations of workmen, and of the acts of the combinations, but most of it has been concerned with questions of torts or crimes, which are without the scope of this book. If indeed a combination of workmen for the ordinary purposes of a trade union were a crime or if making those purposes effective by any combined action were necessarily a tort against persons injured thereby, it would follow that the agreement by which the workmen entered into the combination is invalid and unenforceable as between the parties, but the converse is not true. The contract may be invalid and unenforceable- illegal in the sense in which contracts in restraint of trade are illegal at common law - and yet neither the making nor performance of the contract involve a crime or tort. In England from an early time statutes strictly limited the rights of laborers to refuse to work,80 and made combinations or agreements among them to work only at a fixed rate, criminal.81 As late as 1800 it was enacted that any laborer who entered into any combination to obtain an advance of wages or lessen or alter the hours of work, was punishable by imprisonment,82 and though presumably not enforced for years prior to its repeal, this law kept its place on the statute books until the latter part of the nineteenth century. There could be no doubt then that any agreement of laborers having these objects was illegal while such statutes remained in force, but even if the statutes had not existed it is sufficiently clear that such agreements would have been invalid as between the parties, because in restraint of trade.83 Nor did the common law discriminate in this between master and man.An agreement among manufacturers to give identical rates of wages, hours and conditions of labor to their employees for a year was likewise held invalid,84 though, as has been seen,85 the English law views with far more leniency than that of the United States agreements having for their purpose limiting of competition and fixing of prices. By recent statutes, in England,86 however, trade unions for somewhat limited "statutory objects" have been legalized.87

78 See supra, Sec.Sec. 1630-1632, showing that not the character of the contract but the character of the plaintiff is the basis of the defence of the legality; and infra, Sec.Sec. 1759, 1760, as to the effect of performance, legal when a contract was made, becoming illegal.

79 See supra, Sec.1649. In a proceeding under the Sherman Act the United States Supreme Court has said: "It is suggested that the several acts charged are lawful and that intent can make no difference. But they are bound together as parts of a single plan. The plan may make the parts unlawful." Swift v. United States, 196 U. S. 375, 396, 49 L. Ed. 518, 25 Sup. Ct. 276. See also United States v. Reading, 226 U. S. 324, 57 L. Ed. 243, 33 Sup. Ct. 90. The same principle is applicable to the validity of contracts at common law.