As has been said, wherever a contract is unenforceable at law, ordinarily it is unenforceable in equity.2 Such defences, as fraud, duress, mistake, illegality, which would be ground for a defence, either legal or equitable, to an action at law are a fortiori ground for refusing the equitable relief of specific performance. But conversely there are some contracts which though they may be enforceable at law, and may relate to a subject-matter of which equity ordinarily takes jurisdiction are denied equitable relief. For this reason the jurisdiction of equity is generally called discretionary.5 More exactly it may be said that wherever a contract though legally valid is grossly unfair, or its enforcement opposed to good policy for any reason, equity will refuse to enforce it, and though certain kinds of unfairness may be classified, equity declines to make an exact inventory of what amounts to such unfairness or impropriety as will preclude relief, but leaves a borderland where the court can consider the particular facts of each case and deal with it on its merits. Specific performance will be denied if opposed to public policy, though the contract may not be so clearly illegal that a remedy at law would be denied.4 So if the contract is unconscionable in its terms, equity will not enforce it.5
98 Price v. McKay, 53 N. J. Eq. 588, 32 Atl. 130.
99 See the comments of Professor Pound in 33 Harv. Law Rev. 433.
1 In Jones v. Parker, 163 Mass. 564, 40 N. £. 1044, 47 Am. St. Rep. 485, the obligation enforced was to heat and light certain premises. This involved the installation of proper apparatus and a determination of what was suitable. Holmes, J. met the objection of lack of certainty by saying "If the plaintiff were left to an action at law, a jury would have to determine whether what was done amounted to a reasonable heating and lighting. A judge sitting without a jury would find no difficulty in deciding the same question. We do not doubt that an expert would find it as easy to frame a scheme for doing the work."
2 Supra, Sec.1418.
3 Hess v. Bowen, 241 Fed. 650, 154 C. C. A. 417; Thackaberry v. Kibbe, 284 HI. 109, 119 N. B. 897; Origer v. Kuyper, 183 Iowa, 1395, 168 N. W. 119; Darnell v. Alexander, 178 Ky. 404, 199 S. W. 17; Lake Erie Land Co. v. Chilinski, 197 Mich. 214, 163 N. W. 929; In re Kutz'a Est., 259 Pa. 548, 103 Atl. 293; Bull v. Fallaw, 109 S. Gar. 306, 96 8. E. 147; Woldenberg v. Riphan, 166 Wis. 433, 166 N. W. 21; Hostess Committee v. Zollman, 122 Va. 41, 94 8. E. 164, and oases in the following notes.
A contract by which the defendant contracts to part with his future means of livelihood is looked upon with disfavor and will not be specifically enforced.6 Not only where performance of the plaintiff's contract would involve a breach by the defendant of a contract with a third person, as the plaintiff was aware when he entered into the contract, but even where the agreement of the defendant with the third person was invalid as a contract both at law and in equity for uncertainty, equity has refused to aid the plaintiff because his conduct violated good morals.7
4 Beasley v. Texas & Pacific R. Co., 191 U. S. 402, 48 L. Ed. 274, 24 Sup. Ct. Rep. 164.
5 Chesterfield v. Jansen, 2 Vee. Sr. 125; Mississippi, etc., R. Co. v. Cromwell, 91 U.S.643, 23 L. Ed. 367; Randolph's Ex'r v. Quidnick Co., 135 U. S. 457, 34 L. Ed. 200, 10 Sup. Ct. Rep. 655; Dalsell v. Dueber Watch Case Mfg. Co., 149 U. S. 315, 323, 37 L. Ed. 749, 13 Sup. Ct. 886; Nevada Nickel Syndicate v. National Nickel Co., 96 Fed. 133; Marks v. Gates, 154 Fed. 481, 83 C. C. A. 321, 14 L. R. A. (N. S.) 317; Clark v. Rosario Ac. Co., 176 Fed. 180, 99 C. C. A. 534; Alabama Central R. Co. v. Long, 158 Ala. 301, 48 So. 363; Agard v. Valencia, 39 Cal. 292, 302; White v. Sage, 149 Gal. 613, 87 Pac. 193; Godwin v. Springer, 233 111. 229, 84 N. E. 234; Shoop v. Burnside, 78 Kara. 871, 98 Pac. 202; Jones v. Prewitt, 128 Ky. 496, 108 S. W. 867, 33 Ken. L. Rep. 358; Banaghan v. Malaney, 200 Mass. 46, 85 N. E. 839, 19 L. R. A. (N. S.) 871, 128 Am. St. Rep. 378; Van Noredall v. Smith, 141 Mich. 355, 104 N. W. 660; Aiple-Hemmei-mann Real Estate Co. v. Spelbrink, 211 Mo. 671, 111 S. W. 480; BartJey v. Iindabury, 89 N. J. Eq. 8, 104 Ati. 333; Melton v. Cherokee Oil & Gas Co., (Okl. 1917), 170 Pac. 691, cert denied 247 U. S. 507, 38 S. Ct. 427. In Weegbam v. Killefer, 215
Fed. 168, 171 (aff'd sub nam. Weegh-man v. Killifer, 215 Fed. 289, 131 C. C. A. 558), the court quoted with approval the following extracts: "In Deweese v. Reinhard, 165 U. S. 386, 17 Sup. Ct. 340, 41 L. Ed. 757, Mr. Justice Brewer, speaking for the court, said: 'A court of equity acts only when and as conscience commands, and if the conduct of the plaintiff be offensive to the dictates of natural justice, then, whatever may be the rights he possesses and whatever use he may make of them in a court of law, he will be held remediless in a court of equity.' In Larscheid v. Kittell, 142 Wis. 172, 175, 125 N. W. 442, 443 (20 Ann. Cas. 576) the Supreme Court of Wisconsin said: "The exclusion of a plaintiff from the peculiar favors of courts of equity results equally where his conduct has been unconscionable by reason of a bad motive, or where the result in any degree induced by his conduct will be unconscionable either in the benefit to himself or the injury to others.'" 6Marks 9. Gates, 154 Fed. 481, 83 C. C. A. 321, 14 L. R. A. (N. S.) 317; Marks v. Gates, 2 Alaska, 519; Bates Mach. Co. v. Bates, 87 111. App. 225; Mahaney v. Carr, 175 N. Y. 454, 67 N. E. 903; Ferguson v. Blackwell, 8 Okla. 489, 58 Pac. 647. See also MoCarty v. Kyle, 4 Coldw.
Specific performance may be denied also if the hardship to the defendant of performing will be out of all proportion to the value of the performance to the plaintiff.8 Appreciation or depreciation in value or other events subsequent to the formation of the contract will not ordinarily afford ground for refusing enforcement by equity even though they make the performance of the two parties unequal.9 But if the plaintiff was in default or guilty of gross laches, and the value of the property has materially changed, specific performance may be denied, since otherwise a plaintiff might endeavor to take a speculative advantage of the changes in value.10 Even apart