The law recognizes a right of property in trade secrets.15 As such property loses its only value if the secret is disclosed, any one who acquires knowledge thereof in a confidential capacity, as that of an employee, is under an obligation, which equity will enforce, not to disclose the secret or use it for his own advantage, even if he makes no express contract to this effect.16 It necessarily follows that express contracts which prohibit the disclosure by those entrusted with knowledge of them are v. Murphy, 220 Mass. 281, 107 N. £. 968, L. R. A. 1915 D. 520; Merchants' Legal Stamp Co. v. Scott, 220 Mass. 389, 107 N. E. 969.
14 In Eastern States Lumber Association v. United States, 234 U. S. 600, 614, 58 L. Ed. 1490, 34 S. C. Rep. 951 the court said: "A retail dealer has the unquestioned right to stop dealing* with a wholesaler for reasons sufficient to himself, and may do so because he thinks such dealer is acting unfairly in trying to undermine his trade. 'But,' as was said by Mr. Justice Lurton, speaking for the court in Grenada Lumber Co. v. Mississippi, 217 U. & 433, 440, 'when the plaintiffs in error combine and agree that no one of them will trade with any producer or wholesaler who shall sell to a consumer within the trade range of any of them, quite another case is presented. An act harmless when done by one may become a public wrong when done by many acting in concert, for it then takes on the form of a conspiracy, and may be prohibited or punished, if the result be hurtful to the public or to the individual against whom the concerted action is directed.' "
15 Morrison v. Moat, 9 Hare, 241;
Yovatt v. Winyard, 1 Jac. & W. 394; Peabody v. Norfolk, 98 Mass. 452, 96 Am. Dec. 664; Simmons Hardware Co. v. Waibel, 1 S. Dak. 488, 47 N. W. 814, 11 L. R. A. 267, 36 Am. St. Rep. 755. The principles governing trade secrets are applicable not only to secret processes of manufacture but to unpublished literary dramatic and artistic work. See Board of Trade v. Christie Grain, etc., Co., 198 U. S. 236, 49 L. Ed. 1031, 25 Sup. Ct. 637.
16 H. B. Wiggins Sons Co. v. Cott-A-Lap Co., 169 Fed. 150; Sanitas Nut Food Co. v. Cemer, 134 Mich. 370, 96 N. W. 454; Vulcan Detinning Co. v. American Can Co., 72 N. J. Eq. 387, 67 Atl. 339; G. F. Harvey Co. v. National Drug Co., 75 N. Y. App. Div. 103, 77 N. Y. S. 674; Witkop & Holmes Co. v. Boyce, 61 N. Y. Misc. 126, 112 N. Y. S. 874: "Any one may use it who fairly by analysis and experiment discovers it. But the complainant is entitled to be protected against invasion of its right in the process by fraud or by breach of trust or contract." Dr. Miles Med. Co. v. John D. Eark & Sons Co., 220 U. S. 373, 402, 55 L. Ed. 502, 31 Sup. Ct. Rep. 376.
valid and may be as broad as is necessary to protect the owner from injury by the disclosure of the secret or its competitive use. Especially, contracts by employees may restrain them from disclosing secrets of their employment,17 and the owner of a secret on selling it, may effectively promise not to compete by making use of the process himself or divulging it to others.18 Indeed the sale of a secret process as such carries with it the implied obligation not to disclose it to others.19 But the fact that an article is manufactured by a secret process will not validate a system of contracts for maintaining the price of the article.20 And if a trade secret relates to an article of prime necessity,21 or if the effect of restriction will virtually preclude an employee from ever using his professional or technical skill except in the promisee's employ,22 it is open to question whether courts of equity at least will lend their aid to the enforcement of the promise by injunction. It has been said:23 "Trade Secrets, the names of customers, all such things, which in sound philosophical language are denominated objective knowledge- these may not be given away by a servant; they are his master's property, and there is no rule of public interest which prevents
17 Thibodeau v. Hildreth, 124 Fed. 892, 60 C. C. A. 78, 63 L. R. A. 480; Magnolia Metal Co. v. Price, 66 N. Y. App. Div. 276, 72 N. Y. S. 792; Witkop & Holmes Co. v. Boyce, 61 N. Y. Misc. 126, 112 N. Y. S. 874. A contract also is enforceable by which the employee's compensation is diminished if he leaves his employment for a competitive occupation. Knapp v. S. Jarvis Adams Co., 135 Fed. 1008, 70 C. C. A. 536; Bossert v. S. Jarvis Adams Co., 135 Fed. 1015, 70 C. C A. 23.
18 Dr. Miles Med. Co. v. John D. Park & Sons Co., 220 U. S. 373, 402, 55 L. Ed. 502, 31 Sup. Ct. 376; Chicago Board of Trade v. Christie Grain & Stock Co., 198 U. S. 236, 49 L. Ed. 1031, 25 Sup. Ct. 637; C. F. Simmons Medicine Co. v. Simmons, 81 Fed. 163; Thum v. Tloczynski, 114 Mich. 149, 72 N. W. 140, 38 L. R. A. 200,
68 Am. St. Rep. 469; Grand Rapids Wood Finishing Co. v. Hatt, 152 Mich. 132, 115 N. W. 714; Vulcan Detinning Co. v. American Can Co., 67 N. J. Eq. 243, 58 Atl. 290; Tode v. Gross, 127 N. Y. 480, 28 N. E. 469, 13 L. R. A. 652, 24 Am. St. Rep. 475.
19 .Central Transportation Co. v. Pullman's Palace Car Co., 139 U. S. 24, 53, 35 L. Ed. 55, 11 Sup. Ct. 478; Vickery v. Welch, 19 Pick. 523.
20 Dr. Miles Med. Co. v. John D. Park & Sons Co., 220 U. S. 373, 55 L. Ed. 502, 31 Sup. Ct. 376.
21 See Mallinckrodt Chemical Works v. Nemnich, 83 Mo. App. 6, 13, affd. 169 Mo. 388.
22 See Taylor Iron & Steel Co. v. Nichols, 73 N. J. Eq. 684, 69 Atl. 186, 24 L. R. A. (N. S.) 933, 133 Am. St. Rep. 753.
23 Herbert Morris, Ltd., v. Saxelby.  1 A. C. 688, 714, per Lord Shaw, a transfer of them against the master's will being restrained. On the other hand, a man's aptitudes, his skill, his dexterity, his manual or mental ability - all those things which in sound philosophical language are not objective, but subjective - they may and they ought not to be relinquished by a servant; they are not his master's property; they are his own property; they are himself. There is no public interest which compels the rendering of those things dormant or sterile or unavailing; on the contrary, the right to use and to expand his powers is advantageous to every citizen, and may be highly so for the country at large." The importance of the distinction thus suggested may be conceded, but it will not solve all difficulties arising from restrictive covenants by employees. The objective is frequently so entwined with the subjective, that as a practical matter, a former employee cannot use his subjective skill in competition with his former employer without utilizing objective knowledge gained in his old employment. In such a case all circumstances must be considered, and unless excessive and unreasonable hardship is thereby caused a covenant exacted to protect the employer's business should be enforced even though the employee is thereby deprived of exerting his subjective skill in a particular direction.
Moreover, the inquiry is pertinent whether an employer as a condition of developing a high degree of even purely subjective skill in an employee, may not fairly exact a promise that the skill shall not later be exercised in competition with himself. If the scope of the promise leaves ample opportunity for the exercise of the employee's skill where he will not compete with his old employee, there seems no reason why the promise should be regarded as opposed to public policy, and the American decisions support this conclusion.24