Sec. 162. In general.
Sec. 163 (I) The obligation to make restitution considered upon principle.
Sec. 165. Same: Breach of condition implied in law.
Sec. 167. Same: The doctrine of Britton v. Turner.
Sec. 168. (a) The argument as to inequality.
Sec. 169. (b) The argument as to injustice.
Sec. 170. (c) The argument from analogous cases.
Sec. 171. (d) The argument as to severability of contract.
Sec. 172. (e) Conclusion.
Sec. 173. (II) The state of the law.
Sec. 174. (1) Service contracts.
Sec. 175. (2) Building and like contracts.
Sec. 176. (3) Contracts for the sale of goods.
Sec. 177. (4) Contracts for the payment of money.
Sec. 178. (III) Measure of recovery.
The purpose of this chapter is to consider the rights of one who has partly performed a contract, but is prevented by his own breach from enforcing it. There are few topics which exhibit so clearly the equitable character of quasi contractual obligations. For, notwithstanding the plaintiff's violation of his legal duty, if in reliance upon the broken contract he has conferred a benefit upon the defendant, and the circumstances are such that the retention of the benefit would be inequitable, he is entitled to restitution. Whether, in a given case, however, the plaintiff relied upon his contract or assumed the risk of failure, and under what circumstances the retention of the benefit would be inequitable, are questions upon which marked differences of opinion have developed. The decisions are in such confusion, indeed, that it will be best first to consider the topic broadly and upon principle, and then to endeavor to ascertain the actual state of the law in various classes of cases.