reasons for which it is exercised, there is little analogy between a negative contract and an affirmative tort. If, indeed, a negative contract consist in not doing an act the doing of which equity would prevent as a tort, then equity will also prevent the doing of it as a breach of contract. For example, if a tenant covenant with his landlord not to commit waste on the demised premises, the landlord can have an injunction against the committing of waste by the tenant, either on the ground that it would be a tort, or on the ground that it would be a breach of contract. But the converse of this does not hold; for equity will frequently prevent the breach of a negative contract, though it consist in not doing an act which is not such a tort as equity will prevent, or (which is generally the fact) is not a tort at all.
Nor is there much analogy between negative and affirmative contracts, in respect either to the extent of the jurisdiction exercised by equity over them, or the reasons for its exercise. It is doubtless true that the mere fact of a contract being negative is never in itself a reason why equity should not exercise jurisdiction over it; and, therefore, cases may possibly arise in which equity will enforce a negative contract, and yet proceed independently of the fact that the contract is negative; but such cases will be very rare. And yet the jurisdiction exercised by equity over negative contracts is much more extensive than that exercised over affirmative contracts. Whenever, therefore, equity exercises jurisdiction over a negative contract, it will be found to be almost invariably true that the jurisdiction rests entirely upon the fact that the contract is negative. In what cases, then, will equity assume jurisdiction over a contract upon the single ground that it is negative? First, it seems that equity will always restrain a breach of a unilateral covenant or promise, if it be negative; for, if a covenant or promise is unilateral, it follows that the consideration for it has already been received, i.e., that the covenant or promise has been fully paid for; and, as equity can restrain a breach of a negative covenant or promise without difficulty, it is not thought consistent with justice to permit a person who has given such a covenant or promise, and who has the consideration for it in his pocket, to break his covenant or promise at his pleasure, and thus to leave the covenantee or promisee to such indemnity as he can obtain by an action for damages,—a remedy which may prove worthless, after the expense of obtaining a verdict and judg-