Harm principle

The harm principle holds that the actions of individuals should be limited only to prevent harm to other individuals. John Stuart Mill articulated the principle in the 1859 essay On Liberty, where he argued that "The only purpose for which power can be rightfully exercised over any member of a civilized community, against his will, is to prevent harm to others." An equivalent was earlier stated in France's Declaration of the Rights of Man and of the Citizen of 1789 as, "Liberty consists in the freedom to do everything which injures no one else; hence the exercise of the natural rights of each man has no limits except those which assure to the other members of the society the enjoyment of the same rights. These limits can only be determined by law." It finds earlier expression in Thomas Jefferson's 1785 "Notes on the State of Virginia", Query 17 (Religion) in which he writes, "The legitimate powers of government extend to such acts only as are injurious to others."

John Stuart Mill's formulation

The harm principle was first fully articulated by the English philosopher John Stuart Mill [JSM] (1806–1873) in the first chapter of On Liberty (1859), where he argued that:The object of this Essay is to assert one very simple principle, as entitled to govern absolutely the dealings of society with the individual in the way of compulsion and control, whether the means used be physical force in the form of legal penalties, or the moral coercion of public opinion. That principle is, that the sole end for which mankind are warranted, individually or collectively, in interfering with the liberty of action of any of their number, is self-protection. That 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. His own good, either physical or moral, is not a sufficient warrant. He cannot rightfully be compelled to do or forbear because it will be better for him to do so, because it will make him happier, because, in the opinion of others, to do so would be wise, or even right... The only part of the conduct of anyone, for which he is amenable to society, is that which concerns others. In the part which merely concerns himself, his independence is, of right, absolute. Over himself, over his own body and mind, the individual is sovereign.