People make assumptions all the time, not least about what lefties believe. How many times, for example, have you felt like an argument boils down to “so, you’re left-wing, so you must think X”?

But what assumptions about left-wing people are appropriate? As well as being critical of the wider problems in society, we need to turn our examination inwards and look at ourselves. This is how we build a robust movement. To that end, I have drawn up a list of five basic assumptions I feel it is necessary to make to be on the left. It is not exhaustive, but I do think that if you feel any of these points are invalid, then you are probably not leftwing. In my opinion, they represent core underpinning beliefs.

1. Privilege exists

Or - that the world is unfair. It is important to acknowledge that everyone is given different advantages or disadvantages in life purely based on the circumstances of their birth.

This isn’t to say hard work shouldn’t be valued – it is an unfair accusation that the left favour dependency or handouts. It is to say, though, that if you are born into a well off family you are more likely end up wealthy yourself. Being successful in life (i.e. having lots of money) is not automatically a function of how hard you work, but is determined by how fortunate you are in your birth.

Accepting privilege is an essential leftwing belief. It runs under everything else and is connected to all the other points on this list. It also connected to the idea of questioning authority and what privileges brought someone into a position of authority. Being a woman, from an ethnic minority, gay disabled, or a whole host of other things means you must work harder to be successful, as well as being more likely to face obvious discrimination and harassment compared to a group society has favored with more power.

The Right claim everyone is given an even footing and that success is a result of hard work. But privilege is the crux of what makes society unequal. Biology should not be destiny. The circumstances of your birth should not determine your lot in life.

2. Rational people can be irrational

Not every decision everyone makes is always clearly thought out and considered. This may be obvious, but it’s also very important. Consider the reverse of this point. To lean to the Right you must believe that everyone is rational all the time: criminals make rational choices to commit crimes; addicts choose to continue their addiction; the poor are responsible for their own poverty. This underpins a lot of right-wing policy: criminals should be harshly punished because they chose a life of crime. That the poor deserve to have their benefits cut because they chose not to get a job.

To lean the left is to say that some things are beyond your control and that society should step in and help out in these circumstances. Not just to correct privilege, but because people make irrational decisions and need help to get them out of the situation they have found themselves in. To be left wing is argue against the sentiment ‘you made your decision and now you must pay for it’.

3. Inequality is a bad thing

Having an uneven distribution of wealth and power does not create incentives for those at the bottom of the pile to better themselves but instead creates social strife which in the long run makes us all worse off. This is linked to questioning the fact that those at the top of pile did not get there through their own hard work but through unfair advantages. Why else, for example, are there so many people from rich, privately educated backgrounds in the Cabinet – pure coincidence? Inequality in wealth and power is a symptom of the sickness of privilege.

One of the things I find very strange about the right is when they claim that those who have less should work harder to have more, but society clearly throws obstacles in the way of some and not others. This right wing argument boils down to saying that women should work really really hard to be successful and that men just need to work hard to be successful. Claiming that inequality is a good motivator is just silly.

To be on the left is believe that inequality is caused by privilege and not laziness, and that to defend inequality is to defend a society that privileges some over others.

4. Collaboration is preferable to competition

More can be accomplished by working together than in fighting each other. The free market does not lead to the most socially beneficial allocation of resources. Competition favors privilege – this is why the wealth gap has widened so much in the past three decades.

The right argues that free market competition creates incentives for innovation and that, if left to its own natural devices, it will allocate society’s resources to where they are most needed. Those who are left-wing dispute this and claim that the free market allocates more of society’s scarce resources to the most privileged, rather than to where they will do the most good.

To be on the left is to argue that by working together, through government, collectives or other means, we can achieve a more socially beneficial resources allocation that overcomes privilege. That together we are stronger and that competition divides us.

5. One size does not fit all

Also know as diversity, a phrase much mocked by the right. We are all different, as are our needs. Yet in general society doesn't take this into account, and benefits some over others. This is essence of privilege.

The right argues for a universalist approach. But measuring everyone by the same standard in a clearly unequal society does not work. In contrast, diversity also means accepting that there are valid lifestyles different to yours. It can be hard to accept that others value things differently, some value family more than others, for example. Some value their peers more than their family. It can be hard to understand people with different lifestyles, but everyone deserves dignity, compassion and respect. It should be accepted that one size doesn’t fit all.

Accepting diversity, and that other people live lives completely differently to your own, is essential to being left wing. It is also important to accept that there is not always a single standard of behavior or proper way to do things.

I wanted to show how these problems are interlinked through the idea of privilege, in other words that the circumstances of your birth determine a lot about your life and that society is deeply unfair. Ideas that are essential to how we see the world – and the problems we want to fix.

It is important to always question our own ideas, our own assumptions, and our own privilege. This contributes to both a stronger ideology and a broader movement.