"False premise; invalid conclusion."

Okay... you do realise from the paragraph following that statement we (not merely one) can conclude:

"All one can conclude is that the origin of opposite-sex attraction is multi-factorial, with predisposing and precipitating factors; it is not a mere “choice” but nor is it innate and immutable, as many former heterosexuals can attest."

But there is only one way for you to be taken seriously...

Campaign stridently for the total abolition of divorce (no shortage of scriptural support) including its reversion if a child's mother and father are still alive:

"If marriage is fundamentally about the needs of children and their right, where possible, to be raised by both a mother and a father, a principled party will defend that as policy."

So would a principled GP.

Meanwhile this essay gives a completely different Understanding of this topic. An understanding compatible within a free democratic pluralistic country. And the website on which it is featured gives a much more humorous Understanding of the all important emotional-sexual dimensions of our existence-being:
http://www.adidaupclose.org/Crazy_Wisdom/freedomofchoice.html
Plus Sex Laughter & God-Realization.
http://www.adidam.org/Content/teaching/print-files/sex-laughter-god-realization.pdf

The author wrote: “Changing the definition of marriage, which has lasted from time immemorial, is not an exercise in human rights and equality; it is an exercise in de-authorising the Judaeo-Christian influence in our society.”

The above sentence is nonsense. 'Time immemorial' includes the Bible. Jacob was married to Leah and Rachel. King Solomon had 700 wives and 300 concubines. The Judaeo-Christian influence includes the Bible. The statement is demonstrably untrue even if Australia were a Christian theocracy. However, Australia does not have any official religion, and worldwide customs can be taken into account since Australia is a pluralist society.

In some Muslim countries a man can have as many as four wives. In Tibet until recently a woman could have many husbands. Among North American Indian tribes there was the berdache. A berdache was a male who assumed the female role in every respect including that of marriage to a man.

To use the words 'time immemorial' to refer to a particular marital arrangement which has never been universal shows a lamentable ignorance. Of course one need not concern oneself with facts when asserting the 'eternal' truths of religion.

Davidf
Kinda, Australia has three official religions who all hold the same beliefs, Judeo Christianity, Judeo Islam and Judaism proper the constitution merely prohibits the state from establishing any religion.
I'd also take issue with the term pluralistic in this context.
Try looking at Gay marriage from a different perspective, think of it more as a forced conversion of a heathen tribe than a capitulation by the state and an affront to Christain "morality".
The Roman church said the most appalling things about the Germanic "Barbarians" but they converted them anyway and even allowed the northern tribes to keep some of their eccentric cultural artifacts, Halloween being an obvious example.
Christian morals and tradition are malleable, Sub Saharan Africa's practitioners of "Christian Animism" (Voodoo for those not in the know) are treated with respect by Western Christians, homosexual behavior is easily assimilable compared to animal sacrifice, ecstatic trances and the summoning of nature spirits.

If the Christian lobby believe that their view is the majority view, then let them advocate for a referendum! Bring it on!
Rhrosty.

A “Great” article drawing equally “Great” conclusions…!