What is Sectarianism and Why is it Harmful?

By James E. Petts

This is a summary. Ideas may be simplified. See here for detail.

Sectarianism is when people put the needs of a particular group of people above the needs of people generally in doing something public or political.

For example:

  1. a politician saying, “if you elect me, I’ll take money from all the people in the north and give it to all the people in the south, because the people in the south matter and the people in the north don’t”; and
  2. an organisation that demands that people with blond(e) hair get preferential treatment over everybody else are sectarian.

It is not sectarian to favour particular groups or people in a purely private setting. For example:

  1. a parent giving a birthday gift to her/his child rather than donating the money to charity; or
  2. a sports fan cheering on her/his preferred team, rather than cheering for the best team to win

are not sectarian. (Read here for a more precise description of when favouring a group is not sectarian).

The group that the a sectarian cares about is called the “in-group” and everybody that the sectarian doesn’t care about is called the “out-group”. You can learn more about in-group/out-group bias here.


Trying to do what is best for everybody by weighing all people’s interests equally is called universalism.  Sectarianism is the opposite of universalism. This is because it is trying to do what is best for only some people and ignoring what will happen to everybody else.

This means that a sectarian is likely to be prepared to do extreme harm to members of the out-group to get a very small benefit to members of the in-group. For example:

  1. a government might ban imports from a very poor country to make national producers of that product slightly more wealthy, even if it means that the exporters from the poor country cannot make enough money to live on and may starve to death as a result; and
  2. an activist group campaigning for preferential treatment for blond(e) people might demand that only blond(e) people be appointed to any important jobs, even if they are not properly qualified or competent, causing enormous harm to all the people who rely on those jobs being done properly in return for the slight benefit to a few blond(e) people who get better jobs.


Usually, people who promote sectarianism are part of the in-group. However, sometimes, people who are not part of the in-group promote sectarianism. For example, a person with brown hair might belong to the activist group demanding preferential treatment for people with blond(e) hair. Don’t be fooled by this. So long as some people’s interests are treated as being more important than others’, it is still sectarianism. People might do this for all sorts of reasons, such as to get political power by appealing to the in-group or because of peer pressure.


Sectarianism is ultimately very harmful to everyone. This is partly because it can cause conflict between in-groups and out-groups (including war in some cases). It is also partly because everyone is at risk of being in an out-group. Because sectarianism involves more harm to out-groups than benefit to in-groups, the risk of being in an out-group is much more bad than the chance of being in an in-group is good. Even if you think that you are in an in-group now, you can’t bank on being in an in-group forever.


If you find yourself in an out-group of somebody else’s sectarianism don’t respond by promoting a form of sectarianism where you are part of the in-group. If you do this, you will be part of the problem. Nobody who you want to make part of the out-group will have any reason to listen to you or take you seriously. Why would they? If you don’t care about them, why should they care about you? You will never achieve positive change by doing this – only harm. Sectarianism can never justify more sectarianism.

Instead, focus on ending all sectarianism. Demand that every political idea be accepted only if it can be shown to bring about the greatest good for the greatest number. Demand that everybody’s interests (including yours) be given equal weight. Equally reject forms of sectarianism where you are part of the in-group as you reject forms of sectarianism where you are part of the out-group. Demand that all others do likewise.

Remember – you will always be in danger so long as out-groups are still a thing.

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