Reciprocal Promises to Do Legal and Illegal Things

In one line

Two short sections that save the lawful half of a bargain where section 24 would have destroyed the whole of it, and the difference lies entirely in how the bargain was put together.

In the words a student can write in an exam: section 57 of the Indian Contract Act 1872 provides that where persons reciprocally promise, firstly to do certain things which are legal, and secondly, under specified circumstances, to do certain other things which are illegal, "the first set of promises is a contract, but the second is a void agreement". Section 58 provides that in the case of an alternative promise, one branch of which is legal and the other illegal, "the legal branch alone can be enforced".

Why these sections exist alongside section 24

Section 24 says that where any part of a single consideration is unlawful, the whole agreement is void. Applied without qualification that would be very destructive, because parties frequently record several arrangements in one document, and one bad arrangement would poison all of them.

Sections 57 and 58 identify the two structures in which the lawful part can be cut free with confidence.

Section 57 applies where there are two separate sets of reciprocal promises. Because they are separate, each has its own consideration, and the unlawful set can be struck out without touching the lawful one.

Section 58 applies where there is one promise with two branches, only one of which is unlawful. Because the promisor could always have chosen the lawful branch, holding him to it takes nothing from him that he did not agree to.

Section 24, by contrast, deals with the case where the lawful and the unlawful are paid for together, by one undivided consideration, and there nothing can be separated. See [Agreements Void in Part, and Severability].

Section 57: two sets of reciprocal promises

"Where persons reciprocally promise, firstly, to do certain things which are legal, and, secondly, under specified circumstances, to do certain other things which are illegal, the first set of promises is a contract, but the second is a void agreement."

Its illustration:

"A and B agree that A shall sell B a house for 10,000 rupees, but that, if B uses it as a gambling house, he shall pay A 50,000 rupees for it.

The first set of reciprocal promises, namely, to sell the house and to pay 10,000 rupees for it, is a contract.

The second set is for an unlawful object, namely, that B may use the house as a gambling house, and is a void agreement."

What the illustration shows. There are two bargains inside one document. The sale at ten thousand rupees stands on its own and is enforceable. The arrangement about the gambling house has its own consideration, the extra forty thousand rupees, and its own object, which is unlawful, so it falls. Neither drags down the other.