Instead of merely debating whether same-sex couples should be allowed to marry, we should be debating whether marriage is acceptable at all, said a prominent philosopher and an Israeli feminist on Q&A on Monday night.

Key points: Israeli MP Merav Michaeli argues the origin of marriage has more to do with property than love

Israeli MP Merav Michaeli argues the origin of marriage has more to do with property than love Australian senators say marriage is "the backbone of most families", "foundational to our community"

Australian senators say marriage is "the backbone of most families", "foundational to our community" Michaeli suggests marriage be replaced by formalising financial and social aspects of marriage between any two people

With the postal ballots for the same-sex marriage survey being sent out the day after Q&A was going to air, it was no surprise the program would debate the issue.

However, the first question went much further: With rising divorce rates, should we discontinue our focus on marriage and instead focus on relationships and commitment?

Philosopher AC Grayling, who elected to answer the question as a philosopher rather than as a married man, said the legal institution of marriage is very sexist in its origins and should not exist in that form at all.

"But there's another sense of the word marriage which is the commitment that two or perhaps more — I don't know — people make to one another about pooling their resources, mutually supporting one another," he said.

"In that sense of marriage, what Shakespeare was talking about when he said the marriage of two minds, that's important to us as human beings because we care about the affections and we want somebody to love and be loved by."

Liberal senator Zed Seselja and independent senator Lucy Gichuhi disagreed, calling marriage between a man and a woman "foundational to our community" and "the backbone of most families: and a family is the lowest bedrock of any civil society," respectively.

However, Israeli MP and feminist Merav Michaeli raised a similar distinction to Dr Grayling but in much stronger terms.

"[Marriage was] created back at a time when we women were commodities, as were children, as were men without property and of other colours," she began.

"This is not something that we should maintain in the world when we realise all of us are human beings."

While adamantly endorsing the equality of love, Ms Michaeli said love had nothing to do with the institution of marriage, calling it "a tool made to dominate women for the sake of reproduction".

Labor's Mark Dreyfus said the institution of marriage had changed immensely over the last 4,000 years and is still evolving.

"What we have now is not what Biblical times had as marriage," he said.

Not love, but property

Ms Michaeli, however, argued that marriage is still very much about property in many societies.

When asked directly by an audience member how she could say marriage was not about love when it has historically been about the binding of two individuals who love each other, Ms Michaeli pointed to arranged marriages.

"In many countries … your parents make you marry someone because of their social status, because of the family they come from, because they want to keep the property in a specific family or another family."

Love was "a nice bonus" but was not the reason marriage was created and not why it has lasted, she said.

Ms Michaeli went further when the topic of same-sex marriage specifically was raised.

When Senator Seselja raised the rights of parents over their children's education, for example the right to withdraw their children from gender education classes, Ms Michaeli argued the "core family as we know it" is "the least safe place for children" and helps perpetuate domestic violence.

"The custody, this total custody that we have in this structure of marriage which still gives men domination, complete domination over their children and too often over their women … is a part of the ongoing hurt in children," she said.

Senator Seselja disagreed vehemently that the family is inherently unsafe, and insisted he was very aware of the issues around domestic violence.

"Apparently not," Ms Michaeli said to applause from the audience.

Sorry, this video has expired Zed Seselja and Merav Michaeli disagree over parental rights and safety within the traditional family unit

What could replace marriage?

Host Virginia Trioli challenged Ms Michaeli to provide an alternative.

Ms Michaeli offered two alternative "default arrangements" which could be offered by the state, focusing on child-rearing and co-habitation.

Children could have more than two parents, which would not necessarily by their biological parents but must be someone taking responsibility for the child.

"[They need] to be obligated for certain criteria that the state should actually decide on, what does it mean that you're responsible for the child?"

The other arrangement would take the shared financial and social aspects of marriage and formalise them between any two people, whether they have a shared romance or are simply room-mates.

This, she said, would prevent the explosion that often happens in divorce when financial matters have not been discussed openly.

What about same-sex marriage?

Dr Grayling supported same-sex marriage, saying it was a very different thing to the institution that he and Ms Michaeli objected to.

Ms Michaeli supported what she called the equality of love.

"As much as I'm opposed to the institution, I see no way how civil rights — and as long as the state gives away rights and duties and privileges according to this institution, how can it deny it from part of its citizens. I don't see how that can happen," she said.

Shadow attorney-general Mark Dreyfus said we must have marriage equality while we persist with the institution of marriage in Australia.

On the No side, Senator Seselja specifically referred to marriage between a man and a woman as being the basis of society, and raised concerns over freedom of speech and the rights of parents.

Senator Gichuhi, who has previously warned of "unintended consequences" if same-sex marriage is legalised, referred to attacks upon No campaigners.

The one thing everybody on the panel could agree on was the importance of participation in public debate.

When a teacher asked how to get disillusioned children interested in democracy, every member of the panel had the same answer: Get involved.

Dr Grayling said democracies work very well but only if made to work, and they need activism and engagement to prevent public policy being determined by special interest groups and self-interest.

Mr Dreyfus stressed the importance of participation, saying a lot of Dr Grayling's work emphasised the importance of participation.

Senator Seselja said democracy is the best form of government so we need to make it work, and active involvement of young people keeps political leaders accountable.

Senator Gichuhi said we need to reintroduce civic education in schools, because "if you believe something is broken, you join in and try to fix it."

Ms Michaeli pointed to statistics suggesting a low turnout for postal surveys and asked "How do you make a difference if you're not going to vote? Go vote."