An agreement to do an act impossible in itself is a concept that is often misunderstood in legal circles. In essence, it refers to a situation in which two parties enter into an agreement to perform an act that is impossible to execute, whether due to physical or legal constraints. This type of contract is legally unenforceable, as it is impossible to fulfill the terms of the agreement.

The Indian Contract Act, 1872, defines an agreement as “every promise and every set of promises, forming the consideration for each other,” which means that both parties must be able to fulfill their respective promises. However, an agreement to do an act impossible in itself is an exception to this rule.

For example, if X agrees to sell Y a unicorn, the agreement is impossible to execute, as unicorns do not exist in reality. Similarly, if X agrees to sell Y a house that has already been sold to someone else, the agreement is impossible to fulfill.

The doctrine of impossibility is based on the principle that a contract that is impossible to perform at the time of formation is void ab initio or void from the beginning, and neither party is obligated to perform its part of the agreement. Thus, if X and Y enter into an agreement to do an act that is impossible in itself, the agreement is legally unenforceable.

There are two types of impossibility – physical and legal. Physical impossibility refers to situations where the act is impossible to execute due to natural or physical constraints. For example, if X agrees to jump over the moon, the agreement is physically impossible.

Legal impossibility, on the other hand, refers to situations where the act is impossible to execute due to legal constraints. For example, if X agrees to sell Y a house that has already been sold to someone else, the agreement is legally impossible, as the property is no longer available for sale.

In conclusion, an agreement to do an act impossible in itself is legally unenforceable, as it is impossible to fulfill the terms of the agreement. It is important to ensure that any contract entered into is feasible and possible to execute, to avoid any legal disputes that may arise in the future.