There can be no doubt that Lumley v. Wagner76 and similar decisions violate the rule of mutuality as ordinarily applied to affirmative contracts, and it is important to fix the limits of the exception. It may be supposed, (1) that the negative performance of the defendant, by the terms of the contract is to precede the performance of the plaintiff, (2) that it is to continue pari passu with it or (3) that it is to follow the plaintiff's perform-ance. A fourth case may also be supposed, which partakes partly of the nature of each of the others. The defendant's negative obligation may continue over a considerable period of time. It may be supposed that the plaintiff's performance can be rendered at a single moment, and is due at some time within the period over which the defendant's obligation extends. In every case the plaintiff's application for an injunction must be deemed an election to go on with the contract. Therefore if the plaintiff has already so far broken the contract that he will be unable to perform it substantially or if it appears to the court that for any reason he will not perform in the future on his part, an injunction should not be granted.77 An exception to this principle, however, exists where the defendant's negative stipulation relates to a part of the plaintiff's performance only, and is designed to secure him the enjoyment of the agreed exchange for that part which has been rendered.78
75 Citing for example Tribune Assoc. v. Simonds, (N. J. Eq. 1918), 104 Atl. 386.
76 1 De G. M. & G. 604.
77 Rice v. D'Arville, 162 Mass. 669, 39 N. E. 180.
78 In Rolfe v. Rolfe, 15 Sim. 88, A, B, and C were partners as tailors.
A and B went out of the trade in consideration of receiving £ 1000 each, and G was to continue the business on his own account. A entered into a covenant that he would not cany on, within certain limits, any business like that which he had just sold, and C entered into a covenant that nous with, and dependent upon performance by the plaintiff; and in this case equity will enjoin a breach of the negative covenant so long as the plaintiff is not guilty of a breach of his side of the contract. The alternative is the following:
If the performance of the plaintiff was to proceed pari passu with the performance of the defendant's negative duty, the court can mold the form of the original injunction so that it shall apply only so long as the plaintiff performs on his part.79 The case, however, remains where the negative performance of the defendant must precede the performance of the plaintiff. There seems little suggestion from the courts which follow Lumly v. Wagner that the injunction would be denied on this ground. The defence of allowing the injunction must therefore be, that its allowance will probably result in the full performance of the contract, and that as the defendant, when he made the contract, was willing to run the risk of negative performance on his part, before the plaintiff's performance was due, he cannot fairly complain if equity compels him to take that risk.80