There is a well-worn proposition that politics divides us and there is some truth in this. More often than not, we talk about ourselves and others as being on the right or left of an imaginary political divide.

This has perpetuated, despite the fragmenting of political parties and movements on both sides of the divide.

Read more by JK: My four ideas to fix the world

In his book Politics With Purpose, one-time Labor minister and champion of the left Lindsay Tanner questioned the merits and relevance of the left-right divide in contemporary politics. He suggested that it was no longer relevant for parties to consider themselves left or right, especially given the variance within all political parties on social and economic issues, a point especially relevant in 2017.

Malcolm Turnbull is having real problems in his conservative party because he is economically conservative and socially progressive, while his enemies in his party, like Tony Abbott, are socially and economically conservative. The same is true on the left of politics, where some ‘hard-left’ catholic politicians are economically progressive but socially conservative – like Trotskyites around the world.

I agree with Tanner that the left-right divide is less relevant than it once was. I also agree with the separation of the economic and social perspectives that make up the complete politician. But I believe that there is a more relevant factor that separates us and explains the political divide, and that is ‘starting point’.

This can first be examined from the economic perspective.

All politicians across all political parties are, in 2017, concerned about the ballooning budget deficit and the debt that we are potentially leaving to our children and grandchildren. Although there has always been excessive exaggeration, and a reasonable amount of hot air and hyperbole in this debate, there is no doubt that it is in the country's best interests to reduce the deficit.

How this is best achieved is one of the most significant areas of differentiation between the left and right of the political divide. One solution on the right is to reduce unemployment and social security payments, or make theses payments harder to access, with a view to taking out of the system all of those who are rorting it, while retaining a safety net for those who need it.

Here is where ‘starting point’ comes in. On the right of politics there is a view that money can be saved  by clamping down on rorters, even if the system put in place hurts a number of legitimate claimants. Their view is that if some people are hurt in the quest to clamp down on the rorters, they are legitimate collateral damage. Their starting point is that the saving is more important than the few people hurt.

On the left of politics, it would often be argued that the rorters should be the exception, allowed to exist so than no legitimate claimants are hurt. Their starting point is that when a necessary service needs to be provided to those in need, rorters are an acceptable casualty of what they view as compassionate policy.

This largely gets back to the perspective of politicians, their parties and supporters on the role of the economy, and the community.

The starting point of the right is that the economy is the centre of everything and that the community must serve the needs of the economy. Without a strong economy we have nothing.

The left starting point is that the economy simply serves the community. The community is at the centre of everything and without a strong community we have nothing

The left and the right come at this from different starting points.

The divide on social issues is much less easily explained with the left-right paradigm, but nonetheless, gets back to starting point.

Consider for example the divide found in the refugee debate, where views are readily shared across the left-right political divide.

Social conservatives say that the 600 refugees on Manus Island need to be made an example of to deter further boat people and deaths at sea. Social progressives argue that these 600 people should be treated humanely, even if that means a few more refugees try to get to Australia in the years ahead.

The conservative starting point is that we can sacrifice the few for the cause. The progressive starting point is that we need to show compassion to the few and come up with other strategies to stop future refugees.

Then  there are the pragmatists on both sides, such as Malcolm Turnbull and Bill Shorten, who are only interested in where the votes are. But we'll leave them for another debate.

A similar situation existed with the recent marriage debate. Even after the community poll, conservatives on the left and right in the Senate vote abstained or voted against same-sex marriage, while progressives from the left and right voted for marriage equality.

The conservatives were arguing that extending marriage to the homosexual community legitimised and normalised it, somehow diminishing the status of traditional marriage. I believe that discussion of God in this debate was a distraction.

The starting point for the conservatives was that homosexuals would have to live with not being considered equal, at least in so far as marriage is concerned, for the sake of the broader community.

The progressives were arguing that homosexuality and living in a homosexual relationship was normal and legitimate. They were further arguing that this had no impact on traditional marriage.

The starting point for this group was that it is not fair and reasonable that a portion of the community, albeit a minority, should not be sacrificed in terms of equality just so that the majority can feel more comfortable.

On both of these social issues, the conservatives were prepared to sacrifice the interests of the few for those of the many. On both of these issues, the progressives were not willing to sacrifice the interests of the few for those of the many.

It is interesting to note that in the three examples highlighted in this article, the desire of the right and the conservatives was to address the needs of the many ahead of those of the few – a stance most commonly associated with communism, and that communism, from the political left, is more commonly associated with being harsh on both refugees and homosexuals.

This is a somewhat convoluted way of making two points, Firstly, the left-right political paradigm is less useful today than it has ever been. Secondly, that it is an individual's starting point that determines their political views. It is our starting point that divides us.