Understanding Quasi Contracts and Valid Promises
In contract law, a quasi contract arises when there is no formal agreement, but the law imposes an obligation on one party to prevent unjust enrichment of another. In such cases, consideration is typically absent, which can make a quasi contract void. However, the promise to compensate for finding a lost wallet operates differently.

The Nature of the Promise
- The promise to compensate for finding a lost wallet is a voluntary promise.
- It is based on the principle of rewarding someone for a service rendered or a benefit conferred.

Existence of Consideration
- Unlike quasi contracts, the promise here is supported by consideration.
- When a person finds a lost wallet and returns it, they confer a benefit upon the owner, who then promises compensation.

Legal Enforceability
- This situation creates a valid contract because:
- There is an offer (the promise to compensate).
- There is acceptance (the act of returning the wallet).
- The promise is made with the intention to create legal relations.

Public Policy and Ethical Considerations
- Courts often enforce such promises to encourage ethical behavior and social responsibility.
- Compensating finders promotes honesty and rewards good Samaritan acts.

Conclusion
In summary, while quasi contracts lack consideration, a promise to compensate for a found wallet is valid due to the presence of consideration, mutual agreement, and legal intention to create obligations. This ensures that the finder is rewarded for their honest act, thereby reinforcing social norms.