The concept of principle of reasonableness it is used to refer to a criterion that allows regulate the exercise of rights . The notion refers to the need to ensure that the logic and the common sense prevail at the time of application of the rules.

In the field of labor law , the principle of reasonableness contributes to avoid abuse by workers and employers. For example: the law guarantees that an employer can fire an employee if he commits a fault, but does not allow taking any type of fault as an excuse for the unilateral termination of the employment contract.
In the face of a conflict situation, therefore, a judge has to abide by the principle of reasonableness and assess whether the employer abused his right to fire the worker or if, instead, the exercise of said right resulted reasonable .
Without the principle of reasonableness, the owner of a company could fire an employee who does not like him by resorting to a pointless argument, feeling protected by law. The principle of reasonableness, on the other hand, prevents you from taking advantage of your power to make an arbitrary and unfair decision.
In a broader sense, the principle of reasonableness points to all laws being according to the spirit that has the Constitution national . In other words: the regulations and regulations cannot contradict the provisions of the Magna Carta.
The principle of reasonableness is currently understood as the result of extensive jurisprudence . It is applied in most western societies, analyzing in each case the particularities that merit its invocation.