Sec. 186. In general.
Sec. 187. (I) Improvement of real property.
Sec. 188. Same : Upon principle.
Sec. 189. Same : Measure of recovery.
Sec. 190. (II) Improvement of personalty.
Although cases of mistake as to the ownership of property, real or personal, are neither so frequent nor so various as those of mistake as to contractual rights or duties, they involve the same general principles (ante, Sec. 10 et seq.). Accordingly, one who by the expenditure of money or labor upon property which he mistakenly believes to be his own, confers a benefit upon the real owner of the property, should be allowed to enforce restitution. It will be seen, however, that as a result of supposed considerations of policy affirmative relief at law is generally denied.