On Liberty

On Liberty is John Stuart Mill’s essay on the limits of the power that society may rightfully hold over the individual. Published in 1859, it argues for freedom of thought, discussion and personal life, and it remains one of the most influential works of liberal political thought.

Mill begins by noting that the old struggle between subjects and rulers has changed. Once people govern themselves, it might seem that liberty is safe. Mill warns otherwise: majorities can oppress minorities, and the pressure of social opinion can be more thorough than any law. He calls this the tyranny of the majority.

His answer is a single principle. The only purpose for which power can rightfully be exercised over any member of a civilised community, against his will, is to prevent harm to others. A person’s own good, physical or moral, is not enough. This idea is now usually called the harm principle.

The second chapter, on liberty of thought and discussion, is the most famous. Mill argues that silencing an opinion is wrong even if it is false. If the opinion is true, we lose the truth. If it is false, we lose the clearer understanding of truth that comes from its collision with error. Most often, he says, opinions are partly true and partly false, and only open debate can sort them.

The third chapter defends individuality. Mill admires people who make their own choices and develop their own characters, and he worries about a society in which custom and conformity crush originality. Experiments in living, he argues, benefit everyone.

Mill then considers where the authority of society should begin. Conduct that affects only oneself should be free; conduct that harms others may be regulated, by law or by opinion. Mill also defends people’s freedom to combine with others for any purpose that does not harm third parties, and he treats freedom of conscience, of tastes and pursuits, and of association as the core liberties of a free society.

The final chapter applies these ideas to practical questions, including trade, the sale of poisons, drunkenness, education and the role of the state.

Mill published the essay under his own name, but he described it as a joint production with his wife, Harriet Taylor Mill, who died in 1858 while the final draft was nearly complete. He dedicated it to her memory.