The solution they invented was called the harm principle. It was extremely simple. ‘The only purpose for which power can be rightfully exercised over any member of a civilised community, against his will, is to prevent harm to others,’ they wrote. ‘His own good, either physical or moral, is not a sufficient warrant. In the part that merely concerns himself, his independence is, of right, absolute. Over himself, over his own body and mind, the individual is sovereign.’
