When mutual covenants go only to a part of the consideration on both sides, and when a breach may be paid for In damages, the defendant has a remedy on his covenant, and is not allowed to plead it as a condition precedent.
When a day is appointed for the payment of money, and the day comes before the thing for which the money Is to he paid can be done, then, though the agreement Is to pay the money before the doing of the thing, yet an action may be brought for the money before the performance ; because the agreement is positive that the money shall be paid on that day, and the presumption is that the party intended to rely on his remedy and not on a pre vious performance. .
Benjamin also lays down five rules based on those of Williams, hut not following them in detail. The first combines rules 1 and 2 ; the second, third, and fourth are rules 3, 4, and 5 respectively ; and the fifth is a brief statement, substantially, of the rule of intention of Lord Mansfield in Jones v. Barkley, which it is said "remains unchanged"; Benj. Sales § 561. For these rules of Benjamin see id. § 562.
Dependent promises can only exist as part of the same contract, but more than one con tract may be included in one instrument; Harr. Contr. 159 ; Langd. Sum. Contr. § 115. So, on the other hand, each of two mutual promises may be contained in a separate in strument, each complete in itself and neither making any reference to the other. In such case, it has been said, there is no doubt that each forms a separate unilateral contract; id. § 117.
To be dependent, a simultaneous perform ance must have been Intended; 8 Term 366; Sheeren v. Moses, 84 Ill. 448 ; Kane v. Hood, 13 Pick. (Mass.) 281; it is not sufficient that the performance of promise was intend ed to be within the same period; 11 H. L. Cas. 337. They must be capable of perform ance at the same time and place, and involve an exchange of rights ; Langd. Sum. Cont. § 133 ; but if a time is fixed for the perform ance of one, and not the other, they are 'de pendent; id.; 4 H. & N. 500.
All the stipulations of a contract should be considered in determining the question of dependency, which may be general,—as to the whole consideration on each side,— or, it may exist only as to two distinct promises. Thus a contract may be partly bilateral and partly unilateral and as to the former part, the promises may be dependent.
A unilateral contract, from its nature, can contain only independent promises.
The conditions which must exist to render implied dependency possible are thus enu merated : "1st. The subject of implied de pendency must be a covenant or a promise, as distinguished from a debt. 2dly. The sub ject of dependency and the thing upon which it depends must be of the same nature, i. e.
they must both be covenants or both be promises. 3dly. The covenants or the prom ises must be mutual. 4thly. They must each be a part of the same contract ; and it does not follow that they are so because they are made at the same time, or are contained in the same instrument. 5thly. If in writing, they must each be contained in the same in strument, or in different instruments which refer to each other. 6thly. The contract which contains the covenants or the prom ises must be wholly bilateral, or else it must clearly appear that the covenants or prom ises in question were given and received in payment for each other. 7thly. The per formance of each of the covenants or prom ises must, it seems, be equally certain in le gal contemplation ;" Langd. Sum. Cont. .§ 120.
When the mutual contracts go to the whole of the consideration on both sides, they are mutual conditions, the one precedent to the other, but where a covenant goes only to. a part of the consideration, it is not a condi tion precedent, but an action lies for the breach of it; Howland v. Leach, 11 Pi*. (Mass.) 151; 1 Wms. Saund. 320 e, rules 3 & 4; 29 L. J. Ex. 73. Professor Langdell goes further and insists that two promises are not mutually dependent unless the per formance of one is full payment for the per formance of the other; Sum. Contr. §§ 133, 136 ; but Professor Harriman considers this "theory of equivalency," though "most ingen iously developed," as not "based on satisfac tory authority"; Contr. 158. This difference of opinion between these able writers on the subject is itself sufficient to show that the point is not definitely settled. Possibly the lack of precise authority upon this single point of a subject, of which the substantial principles have been settled for more than a century, might be considered as fairly in dicating that it is more interesting than ma terial,—rather theoretical than practical. See [1894] App. Cas. 266. It should, perhaps, rather be said that differences of opinion (of which another on a very practical point is noted infra) between these two writers who have, more than any others, philosophically examined the subject, indicate that the gen eralizations of Mr. Serjeant Saunders, while containing the essential principles, are to be applied only with some modification to mod ern conditions. It is therefore essential that the student or practitioner in dealing with particular cases should include in his re searches both the ancient learning and the modern investigations which have illuminat ed the topic. To these it is hoped that this title may furnish a reference,—it is mani festly possible to do little more, in the way of critical examination and comparison of cases.