Article 23. Even when an act or event causing damage to another's property was not due to the fault or negligence of the defendant, the latter shall be liable for indemnity if through the act or event he was benefited. 

-      What is contemplated by Article 23 is an involuntary act or an act which through unforeseen could not have been avoided. This is based on equity. 

Duty to Indemnify because of Benefit Received

       

-      Unless there is a duty to indemnify, unjust enrichment will occur.

Example

Without A’s knowledge, a flood drives his cattle to the cultivated highland of B. A’s cattle are saved, but B’s crop is destroyed. True, A was not at fault but he was benefited. It is but right and equitable that he should indemnify B. (Report of the Code Commission, pp. 41-42)

In the above situation, if there is no duty to indemnify or to pay for just compensation, B would unfairly benefit by chance and misfortune of A in which B has not worked or paid for.

Here unjust enrichment is an equitable doctrine applied in the absence of a contract and used to prevent one person from being unjustly enriched at another’s expense.

Sources:

*The Civil Code by Paras 2008 Edition

*Family Code of the Philippines by Albano 2017 Edition

*USLEGAL definition