A more thorough explanation:

Insanity refers to a legal defense used in criminal cases where the defendant claims that they were not mentally capable of understanding the nature of their actions or that their actions were wrong at the time of the crime.

For example, if someone with a severe mental illness commits a crime, they may be able to use the insanity defense to avoid being found guilty. However, this defense is not often successful and requires extensive evidence and evaluation by mental health professionals.

The insanity defense is based on the idea that it would be unjust to punish someone who was not in control of their actions due to a mental illness or defect. It is a complex and controversial legal concept that is not always accepted by courts.