The harm principle says people should be free to act however they wish unless their actions cause harm to somebody else.

The principle is a central tenet of the political philosophy known as liberalism and was first proposed by English philosopher John Stuart Mill.

The harm principle is not designed to guide the actions of individuals but to restrict the scope of criminal law and government restrictions of personal liberty.

For Mill – and the many politicians, philosophers and legal theorists who have agreed with him – social disapproval or dislike for a person’s actions isn’t enough to justify intervention by government unless they actually harm someone.

The phrase “your freedom to swing your fist ends where my nose begins” captures the general sentiment of the principle. The approach is usually linked to the idea of ‘negative rights’, which are demands someone does not do something to you.



The limitation of state power

On the other side, ‘positive rights’ demand things are done for you, like the provision of healthcare or welfare payments. For this reason, the principle is often used in political debates to discuss the limitations of state power.

There’s no issue with activities that are harmful to the individual themselves. If you want to smoke, drink, or use drugs to excess, you should be free to do so. But if you get behind the wheel of a car whilst under the influence, pass second-hand smoke onto other people, or become unpredictably violent on certain drugs, then there’s good reason for the government to get involved.

Attempting to define harm

The sticking point comes in trying to define what counts as harmful. Although it might seem obvious, it’s actually not that easy. For example, if you benefit by winning a promotion at work while other applicants lose out, does this count as being harmful to them?

Philosopher Joel Feinberg would argue no: he defines harms as “wrongful setbacks to interests”. He would argue you wouldn’t be harming anyone by winning a promotion because although their interests are set back, it wasn’t done in a wrongful manner.

A more difficult category concerns harmful speech. For Mill, you do not have the right to incite violence – this is obviously harmful as it physically hurts and injures. However, he says you do have the right to offend other people – having your feelings hurt doesn’t count as harm.

Recent debates have been questioning this and saying certain kinds of speech can be as damaging psychologically as a physical attack – either because they’re personally insulting or because they entrench established power dynamics and oppress minorities.

Importantly, Mill believed the harm principle only applied to people who are able to exercise their freedom responsibly. For instance, paternalism was still justifiable for children (which makes sense, seeing as paternalism means ‘governing as though a parent over children’).

Unfortunately, he also thought these measures were appropriate to use against “barbarians”, by which he meant non-Europeans in British colonies like India.

Although some might see this as a side note, it does highlight an important point about the harm principle: the basis for determining who is worthy or capable of exercising their freedom can be subject to personal, cultural or political bias. And that is not good.

Join the conversation

How do you determine what is harmful to another?