I would like to start off where Senator Dastyari left off: I think all views should be respected in this debate, and I certainly respect colleagues, friends and family who have a different view to my own—which is in support of traditional marriage. 

I also want to say, up-front, that I support the removal of any practical discrimination against homosexuals and same-sex couples. We should ensure that happens. I believe we have largely achieved that, over a period of time. However, if there are instances of discrimination against same-sex couples, they should be removed. Whether or not the definition of marriage in our existing legislation is discrimination itself is a matter for debate, in my view. It is a matter that we need to consider very clearly. We should consider it very clearly because the definition in our Marriage Act today has been the same for centuries—for millennia. Not just in our culture and not just in the religions that have been common in this country but in almost every culture in the world, over the span of millennia, marriage has been an institution that enshrines the union of a man and a woman, often with the intention of creating children.

I fully admit that, in modern times in this country and in developed countries generally, marriage has had a tough time of it in the last few decades. The experience and stability of many marriages has been more difficult, or less consistent, in the past few decades than previously in other generations and in other cultures. I believe that is unfortunate. It is a great tragedy when marriages break down, particularly where children are involved. I believe that firmly from my own personal experience, and I also believe that firmly from the evidence that exists about the importance of a child having a biological mother and father to raise them. Of course, that does not always happen and it cannot always happen. Tragedies occur and unfortunate things happen in our society, but just because we cannot make things perfect it does not mean that we should not strive for perfection. Just because something is good and not perfect it does not mean that we should make it the enemy of the perfect. I still believe that we should, regardless of what may happen to our marriage legislation in this country in the next few years, passionately defend and support the institution of family and passionately defend and support the importance of mothers and fathers staying together to look after the kids, because every time that that cannot happen it is a very difficult situation for the children involved.

As I said, I have come to this position not from a religious perspective but, in the first instance, from a personal perspective. My own father's father took off when my father was a little kid. I do not want to go into all the details, but my dad is a great bloke. I am very lucky to have been raised by my father. He is a courageous man and he has taught me a lot in my life, but he would still say it is a tragedy that he did not have a father himself for most of his life and did not have that support of his own father to guide him through life. While he is a great man, he has made mistakes in his life and it is unfortunate that he did not have the stability that he and Mum were able to provide for me and my brother and sister through our growing and formative years.

I myself have four sons. They are still in those formative years, and every day I try to maintain my relationship not just with my wife but with my sons. It is hard, in this job, to do that sometimes. It is hard to communicate with 10-year-old boys over the telephone or through Skype. You ask them what they did during the day and they usually say, 'Nothing.' You ask them what they learnt at school and they say, 'Stuff.' They are not particularly communicative. But I feel it is extremely important—my job as a dad is much more important than my job as a senator. I do my best to perform that role as a father because I think having a father and being a dad is extremely important.

The combination of a mother and a father makes for a very nurturing and supportive environment for children. I want to say that it is not just my personal experience. The evidence on this is abundantly clear on the best outcome for children, on average. There are loving families of many different types but, on average, the best outcome for a child is for their biological mother and father to remain together, married, and support their development.

There is a very considered and meritorious sociologist in the United States, Dr Charles Murray, who wrote a book recently called Coming Apart. It is largely about the US and not about Australia. It is not just about marriage, but is about, more generally, the progress and development of white America. He has not included ethnic communities because they have other issues. He shows, very clearly, across a range of different measures, including delinquency in adolescent, sexual choices, teenagers and crime rates, that the outcome, on average, is best for children when they are raised by their biological mother and father who remain married.

Another very famous person in the United States, President Barack Obama, wrote a very moving book called Dreams from my Father where he very eloquently stated how much of a tragedy it was that his father did not remain with him for very long during his upbringing, and the great vacuum and hole that that put in his life. While President Obama obviously has a different view to me about the institution of marriage, regardless of what happens in this debate, we should not in any way downplay or diminish the importance of a mother and a father for children.

When we look at the institution of marriage and what it means, it has in fact almost always been about the creation of children. It is not actually an institution that is primarily a religious or Judeo-Christian one. In our Western European culture the word 'marriage' does not come from a Jewish route or a religious route; the word is actually a Latin word. It comes from the word 'matrimonium'. In Latin 'matrimonium' is a combination of two concepts, 'matri' meaning mother and 'monium' meaning the state of being or condition. The very word that we use today, 'marriage', actually has roots in our culture about the creation of children or of being a mother. That is what it was in Roman society, which was not a Christian society, not a Jewish Society and not a monotheist society. It was a society, of course, where homosexuality was accepted and was common practice, but it was also a society that had a very defined view, institution and word for marriage.

Marriage is important in many religions in the world as well. In many religions the sacrament of marriage is associated with the union of a man and a woman and is associated with becoming one flesh in terms that are often using Christianity. While we often, in modern times, take becoming one flesh as a metaphorical concept for the union of two people, its roots have a more direct and practical grounding in the creation of children. The creation of a child is literally the becoming of one flesh, the union of two people into one flesh, through the genetic diffusion of two people into one human being. I think that there is nothing much more miraculous in our world than the creation of children. This particular institution that we have, called 'marriage', has been established to nurture and support that phenomenon.

Like many of our institutions, which have been handed down to us over time, marriage is perhaps something that we do not conceive the importance of. In the world of science we have a wonderful, open, free, prosperous society because we stand on the shoulders of giants that went before us. Like Isaac Newton said, we are very lucky and fortunate because of what has happened before us and because of what has been created before us. Marriage is one of those things that has been created and protected over centuries before us. I worry that, if we were to tinker with what marriage means, we would lose something from our society. We would lose a cultural institution from our society that we would struggle to recapture.

In some respects I recognise that this particular debate is a semantic one. It is a debate about the definition of a word. What should the word 'marriage' mean? Should it mean, simply, the union of two people who love each other, or should it mean the union of two people who not only love each other but can create a child? While it is often said that semantic debates are important and it does not matter, I disagree. I think words are important. I think that language is important. Ludwig Wittgenstein said that, if I do not have a word to describe something, I cannot conceive of it. The limit of my world is the limit of my language.

I worry that, if we redefine the scope of what marriage means and is defined as, we will lose our ability as human beings to conceive of a very important, albeit, narrow human relationship which is the union of a man and a woman to create a child. That word is important to describe that particular relationship. That is not to denigrate or say that other types of human relationships are in any way inferior or superior, but that this particular relationship of a man and a woman coming together to create children is different. It is unique, it is diverse. Those other relationships—mother-father relationships, brother-sister relationships, homosexual relationships—are clearly very different from a relationship which comes together to create a child. I believe that we should have a separate institution that allows us to conceive of that particular relationship. 

We should have a word that describes that particular relationship, and if we change the definition of marriage to not describe that particular relationship, we will lose our ability to conceive of and protect that particular idea and institution. That is not to say that we could not find other ways in our society to do this. I am just concerned that we would rush to change an institution so quickly without any real plan or conception of how we are going to celebrate the diversity of heterosexual relationships—which are obviously, by definition, the only relationships that can create children.

Sometimes the proponents of a change to the Marriage Act in this debate say that marriage is all about love, and they say, 'How can you be against two people coming together and being in love?' I absolutely accept that love is a necessary condition for a successful marriage, but it is not a sufficient condition for a marriage as we define it now. Marriage is not only about love. It is also about sacrifice, because when you get married you cannot do certain things that you used to be able to do. It is also, as I have said comprehensively in this speech, about the creation of children. It is something different. It is something diverse. The proponents who want to change this particular act often say at the same time that they want to celebrate diversity. They say they want to celebrate different points of view, different cultures and different ideas; but, in fact, a change to the Marriage Act in the way that this bill seeks to do would  not be a celebration of diversity but a celebration of uniformity, because it would make all relationships that simply involve love between two human beings the same. There would not be a celebration of diversity; there would not be an acceptance of different types of humanity and different types of human relationships, and I think that would reduce and remove some of the colour and imagination that goes with being a human being, and I hope that change is not made.

Regardless of how this debate evolves, I do hope that respect is given to different points of view in this debate. This week I have been attacked by some fellow senators and have been called a bigot for my views on this issue—by my follow senators. What I do not quite understand is that some of those senators who throw around these attributes would also say that they respect different religions and cultures and that they welcome migration to our country. They also say that they would protect the poorer in our society. I accept that at the moment there is popular support for a change, albeit the evidence is rather superficial, but there are also clearly many groups in our society who do not support a change. For example, if you look at the Australian National University survey on political views that is done after every election, only 15 per cent of people of the Muslim faith support a change to the Marriage Act. Are the 85 per cent of Muslims who do not support a change bigots? Are the 60-odd per cent of Catholics who do not support a change bigots? Are the majority of people on low incomes who do not support a change bigots as well?

The other striking thing about the evidence about who does and who does not support marriage in our community is that it is, in fact, a luxury good. The higher your income the more likely you are to support marriage. I do not know why that is the case; I can only surmise. But I would say that I grew up in a relatively low-socioeconomic area where divorce rates were quite high during my time as a child, and I had many friends whose parents' marriages did not last. Whereas, if you look at the evidence, if you were lucky enough to live in a leafy, well-to-do suburb in our society, it is most likely that your parents stayed married. In my view it is the working class areas of our communities that know and understand the importance of this institution, that know and understand the effects and consequences of a diminution in the importance of marriage and its effects on the wider family environment. I hope not only that views are respected in this debate but also that any change we may make to the law respects the different views. Looking at this particular bill, I do not believe that it duly respects those different views.

This bill does exempt ministers of religion from solemnising same-sex marriages but it does not extend that exemption to individual civil celebrants or to ministers of religion whose religion does not have a view on same-sex marriage or supports same-sex marriage. I do not think that is a sufficient protection of individual rights—and they are individual rights. These rights that we have, particularly the freedoms of religion and belief, are fundamental in our society. Those rights are not something that is held by the Catholic Church or an Islamic mosque or a Buddhist temple. Those rights reside in each individual. Each Australian has the right to hold a view about a particular issue and we should respect those views. For me, any change to the Marriage Act which does not duly respect those views would be a contravention of the fundamental rights of every Australian and would be in contravention of the international agreements on human rights that we have signed—one of which is the International Covenant on Civil and Political Rights. Article 23 of that covenant obliges signatories to protect and support the creation of families through marriage between a man and a woman. The interpretation of that provision by the UN Human Rights Committee has been that there is no obligation on states to change their marriage acts to include same-sex couples. In my view, because there is no obligation according to the United Nations, there is certainly no rationale for forcing Australians with a different view to solemnise same-sex marriages.

I look forward to a wider debate on this issue over the coming years. I will return to where I started. I hope that there can be a respectful debate, an informed debate, and that any change we make to an institution that has lasted centuries is made after such a debate.