Two arguments have been advanced in support of the latter new, First, it has been said that the parties to the first aereement had either of them a right to subject himself to liability in damages if he preferred to pay damages rather than to perform the contract; and, therefore, it is contended, the surrender of the right to pay damages constituted a sufficient consideration.14 The argument is, however, unsound. It is doubtless true that a promisor can always refuse to perform his promises, and in most cases the only liability he incurs thereby is to pay damages, but this is far from saying that when one enters into a contract he in effect agrees to perform or pay damages at his option. Under ordinary contracts his duty is to perform the contract, and his co-contractor is entitled to the performance.14a Unless, therefore, he has reserved as an alternative in the contract the choice of making a money payment to the promisee, he does not perform his legal duty by paying damages.15 Moreover, even if it could be conceded (as it cannot be) that the original promise is to be regarded as merely an alternative undertaking either to perform or pay damages, the situation here under discussion would not be helped at least if the second agreement were bilateral; for the same construction would have to be put upon the second undertaking as upon the first. One who was previously bound to do certain work or pay damages based on its value, is promising nothing detrimental to himself or beneficial to the promisee when he again promises to do that very work or to pay damages necessarily identical in amount with those for which he was previously liable. The other ground suggested for supporting the second agreement is that the first agreement is rescinded by the second, and being rescinded, each party, freed from previous obligations, may enter into the new agreement. It must be conceded that the original agreement if still in part at least unperformed on each side, may be rescinded by mutual consent; 16 and, if the original agreement is rescinded, a new agreement made thereafter on any terms to which the parties assent will be binding. Therefore, a rescission followed shortry afterwards by a new agreement in regard to the same subject-matter, would create the legal obligations provided in the subsequent agreement. It must further be conceded that when a second agreement is made which is intended by the parties as a substitution for the original contract, there is mutual assent to the rescission of the earlier agreement. But calling an agreement an agreement for rescission does Dot do away with the necessity of consideration,17 and when the agreement for rescission is coupled with a further agreement that the work provided for in the earlier agreement shall be completed and that the other party shall give more than be originally promised, the total effect of the second agreement is that one party promises to do exactly what he had previously bound himself to do, and the other party promises to give an additional compensation therefor. If for a single moment the parties were free from the earlier contract so that each of them could refuse to enter into any bargain whatever relating to the same subject-matter, a subsequent agreement on any terms would be good.18 The situation is not different from that existing where one subject to a unilateral obligation. undertakes instead of merely performing that obligation to do something additional,19 nor indeed from that where one subject to no liability voluntarily agrees to assume one.20 In a few cases Carstens a distinction has been taken which, however equitable it may seem, also involves faulty reasoning. It is held in these cases 21 that "where the party refusing to complete his contract does so by reason of some unforeseen and substantial difficulties in the performance of the contract, which were not known or anticipated by the parties when the contract was entered into, and which cast upon him an additional burden not contemplated by the parties, and the opposite party promises him extra pay or benefits if he will complete his contract, and he so promises, the promise to pay is supported by a valid consideration." The difficulty with this suggestion is that the unknown and unanticipated difficulties do not excuse the contractor from fulfilling his original contract.22 Accordingly in acting under the second offer, the contractor is merely doing or promising to do something which at the time he was under obligation to do, and which the promisee was entitled to receive. In any case, however, if the terms of the new agreement vary the character of the work which the contractor is to do, there is sufficient consideration for the new bargain. If one party to a bilateral contract has fully performed, a promise of additional performance by him made in order to induce the other party to perform, and which does induce him to perform is even more clearly without consideration than where the new agreement is made before either party has fully performed.23 The case is identical in principle with an agreement in consideration of the payment of a liquidated debt.24 Similarly a promise by an employer or an employee under a subsisting contract to do more or take less than that contract requires is invalid unless the other party gives or promises to give something capable of serving as consideration.25 And a promise by a landlord to do something not required by the lease is not supported by the tenant's promise to perform obligations to which he is bound by the lease.26

So 884, 28 L. R. A. (N. S.) 450, 139 Am. St. Rep. 19; McDonough v. Saunders (Ala.), 78 Bo. 160; Feldman p. Fox, 112 Ark. 223, 164 8. W. 766; Main Street Co. p. Los Angeles Co., 129 Cal. 301, 61 Pac. 937; Benedict Greer-Robbins Co., 26 Cal. App. 468, 147 Pac. 486; Benford v. Yockcy (Colo.), 164 Pac. 725; Littlepage v. Neale Publishing Co., 34 App. D. C. 257; Bush p. Rawlins, 89 Ga. 117,14 S. E 888; Davis p. Morgan, 117 Ga. 504, 43 S. E. 732, 61 L. R. A. 148, 97 Am. St Rep. 171; Willingham Sash Co. v. Drew. 117 Ga. 850, 45 8. E. 237 (cf. Poland Paper Co. v. Foote, 118 Ga. 458, 45 S. E. 374); Nelson v. Pickwick Asso-ciated Co., 30 11. App. 333; Golds-borough v. Gable, 140 111. 269,29 N. E. 722, 15 L. a. A. 294; Moran v. Peace, 72 111. App. 135, 139; Allen v. Rouse, 78 111. App. 69; Mader v. Cool, 14 Ind App. 299, 42 N. E. 945, 58 Am. St. Rep. 304; Ayres p. Chicago, etc., R. Co., 52 Iowa, 478, 3 N. W. 522; Mccarty p. Hampton Bldg. Assoc, 61 Iowa, 287,16 N. W. 114; Awe p. Gadd, 179 Ia. 520, 161 N. W. 671; Howard p. McNeil, 25 Ky. L. Rep. 1394, 78 S. W. 142; Wescott p. Mitchell, 95 Me. 377, 50 Atl. 21; Parrot p. Mexican C. R. Co 207 Mass. 184, 93 N. E. 690, 34 L. R. A. (N. S.) 261; Bell v. Oates, 97 Miss. 790, 53 So. 491; Lingenfelder p. Wsinwright Brewing Co., 103 Mo. 578, 15 8. W. 844; Storck p. Mesker, 55 Mo. App. 26; Wear v. Schmelzer, 92 Mo. App. 314; Smith v Sickenger (Mo. App.) 202, 8. W. 262; Easterly v. Jackson, 29 Mont. 496, 75 Pac. 357; Eastely Harvesting Machine Co. v. Pringle, 41 Neb. 266, 69 N. W. 804; Voorhees v. Woodhull's Exr's, 33 N. J. L 494; Natalizsio p. Valentino, 71 H. J. L. 500, 502, 59 Atl. 8; Bartlett v. Wyman, 14 Johns. 260; Vanderbilt v. Schreyer, 91 N. Y. 392; Carpenter v. Taylor, 164 N. Y. 171, 58 N. E. 53; Weed v. Spears, 193 N. Y. 289,86 N. E. 10; Schneider p. Heinsheimer, 55 N. Y. Supp. 630, 26 N. Y. Misc. 11; Jug-hardt v. Reynolds, 68 N. Y. App. D. 171, 74 N, Y. Supp. 152; Moore p. Bloomingdale, 126 N. Y. Supp. 125; Galway v. Prignano, 134 N. Y. Supp. 671; United Merchants' Press v. Corn Products Refining Co. (N. Y. App. Div.), 134 N. Y. S. 578; Kuhmarker Mfg. Co. p. Hills, 146 N. Y. S. 1013; Seneca Falls p. Botsch, 86 N. Y. Misc. 481, 149 N. Y. S. 320; Festerman v. Perker, 10 Ired. 474; Muir v. Morris, 80 Ore. 378, 154 Pac. 117; Erb v. Brown, 69 Pa. 216; Jones p. Risky, 91 Tex. 1, 32 8. W. 1027; Whitsett p. Carney (Tex. Civ. App.), 124 8. W. 443; Creamery Package Mfg. Co. p. Russell, 84 Vt. 80, 78 Atl. 718; Tohnie p. Dean, 1 Wash. Ter. 46; Vance P. Ellison, 76 W. Va. 592, 86 S. E. 776; Magoon p. Marks, 11 Hawaii, 764. See alto Hartley v. Ponsouby, 7 E. & B. 872; Eastman v. Miller, 113 Ia. 404, 85 N. W. 635; Proctor p. Keith, 12 B. Mon. 252; Eblin v. Miller's Exec'r, 78 Ky. 371; Endriss v. Belle Isle Ice Co., 49 Mich. 279, 13 N. W. 590; Conover p. Stillwell, 34 N. J. L. 54, 57; Hanks p. Barron, 95 Tenn. 275, 32 S. W. 195; Boerger p. Vandegrift (Tex. Civ. App.), 188 S. W. 948; Smith v. Brown (Utah), 165 Pac. 468; Thomas p. Mott, 74 W. Va. 493, 82 S. E. 325. A promise by a contractor to do work beyond what the contract required in consideration of the contract being carried out by the other party is equally invalid. Jughardtv. Reynolds, 68N.Y. App. Div. 171,74 N. Y. 8upp.l52;Gaax v. Green, 6 N. Dak. 48, 68 N. W. 313.