What do you mean by the doctrine of 'Quantum Meruit' under Indian Contract Act, 1872? State the circumstances under which this doctrine may be applied.

Meaning of 'Quantum Meruit': The term "Quantum Meruit" literally means "as much as earned" or "reasonable remuneration". It is used where a person claims reasonable remuneration for the services rendered by him when there was no express promise to pay the definite remuneration. Thus, the law implies reasonable compensation for the services rendered by a party if there are circumstances showing that these are to be paid for. The general rule is that where a party to a contract has not fully performed what the contract demands as a condition of payment, he cannot sue for payment for that which he has done. The contract has to be indivisible and the payment can be demanded only on the completion of the contract. Circumstances under which this doctrine may be applied: When the original contract is discovered to be void: If a contract is found to be void, and a person has performed some work or rendered some service under it, they may claim reasonable compensation for the work done. When an act is done without any intention to do so gratuitously: If a person does something for another, not intending to do it gratuitously, and the other person enjoys the benefit of the act, the former can claim compensation for the work done. When one party prevents the other from completing the contract: If one party who has performed part of his contract is prevented by the other from completing it, he may sue on a quantum meruit, for the value of what he has done. When the contract is divisible and the party in default has had the benefit of the part performed: The party in default may also sue on a "quantum meruit" for what he has done if the contract is divisible and the other party has had the benefit of the part which has been performed. But if the contract is not divisible, the party at fault cannot claim the value of what he has done.