Something absolutely indispensable or essential/ condition without which it could not be.
The Latin phrase refers to an essential condition or qualification; an indispensable thing or absolute prerequisite. It is a circumstance in which a certain act is a material cause of a certain injury or wrongdoing, without which the injury would not have occurred. In the law of torts, a causal connection exists between a particular act and an injury. This is known as the rule of sine qua non.
A left his keys in the ignition and went to buy something in a nearby store. Meanwhile, his ten-year-old son ‘B’ started the car and backed it over, causing serious damage to C’s bike which was parked right behind A’s car. In this case, if A had not left the keys in the ignition, his son could not have started the car and backed it over C’s bike. Thus, A’s act was the sine qua non of the damage to C’s bike.
In Yunis @ Kariya vs the State of Madhya Pradesh, the Supreme Court held that “In the present case, the illegal acts of the accused persons have resulted in the death of a young boy of 18 years. Where the ocular evidence is very clear and convincing and the role of the accused person in the crime stands clearly established, the formulation of motive is not a sine qua non for proving the prosecution case.”
In Dr. Rajendra Prasad Agarwal vs Union of India And Another, the Allahabad High Court held that “the requirement of the law is that the formation of opinion, which is a sine qua non for exercise of power must be demonstrable from the notification and for the purpose of objectivity of the material Government record could be looked into.”