"It's good to know that if I behave strangely enough, society will take full responsibility for me."
PS: I noticed that a lot of people land up on this post while googling up "McNaughten Rule".
One, I just found out that the spelling slightly different. Its McNaughton Rule (or M'Naughten Rule).
Two, here's the actual rule, "...it must be clearly proved that, at the time of committing the act, the party accused was labouring under such a defect of reason, from disease of the mind, as not to know the nature and quality of the act he was doing, or, if he did know it, that he did not know he was doing what was wrong."
More info on the rule at Wikipedia.