Twenty-eight years ago, the word "AIDS" entered our language and entered our hearts.
Only two years earlier, a great Australian, Professor Frank Fenner had proclaimed the eradication of smallpox, seemingly bringing to an end the long centuries of suffering caused by major disease.
But it was not to be.
In HIV/AIDS, humanity had acquired an even more stubborn and formidable enemy than the diseases which had gone before.
And the scale of the devastation has been almost beyond imagination:
More than 25 million people have died from AIDS.
Another 35 million live with the condition.
A majority of them are women and children.
And almost all of them live in the regions of the world least able to bear the cost.
It is - in every sense - a catastrophe and a crisis.
Tonight, on the eve of World AIDS Day, we light these two great public buildings in the colour so closely associated with emergencies, and that is appropriate for the scale and impact of this pandemic.
Friends, with this red lighting, we proclaim a day of mourning for our brothers and sisters who have been lost.
Each of them is loved and each of them is remembered.
But with this lighting, we also proclaim a renewal of hope because though we cannot cure AIDS at present, we do know how to curb and control it.
Through education and some very basic public health tools such as condoms and needle exchanges, we can prevent the spread of HIV.
Australia's brilliant response since 1983 proves how effective those tools can be.
And thanks for that go not only to courageous governments from both sides of politics, well supported by clinicians and experts, but also thousands of volunteers, carers and activists, many in organisations represented here.
Your work has ensured that a tide of care and compassion overwhelmed the forces of ignorance and doubt - and you have my admiration and my thanks.
So a huge role for prevention and education - which as Bill Bowtell reminds us, are still the cheapest and simplest tools for combating HIV/AIDS.
But since the 1990s, we've also had combination drug therapies that can slow and sometimes even halt the progress of AIDS, saving lives and enhancing the quality of life.
And I say today:
? Those drugs belong in the hands of everyone living with HIV,no matter who they are or where they live.
HIV/AIDS has no boundaries.
Nor should our response.
Friends, if there is hope amid the pain and loss of AIDS, it comes from people like Bono and Bill and Melinda Gates.
Their message is a message of hope.
A message that with adequate funding, coordination and goodwill, HIV/AIDS can be mitigated and overcome.
That is the hope that unites us today.
But more than hope, we also need a sense of urgency because while this condition is now preventable and treatable, the scope of AIDS is destroying entire social and economic structures in the countries where it prevails in the developing world.
There is also a sense here in Australia and other developed nations that the prevention message is being lost as new generations grow up and complacency sets in.
There is no room for complacency in the HIV/AIDS debate.
This battle is not yet won, and we have not yet done enough.
So let us take the opportunity of World AIDS Day 2010 to pledge more.
Yes, more funding.
But also more understanding.
And a more insistent focus on the basics of education and prevention that we know can and do work.
So as we illuminate these great buildings, let us keep the light of hope burning in our hearts, until we can stand together, like Frank Fenner did with smallpox 30 years ago, and say the journey is over and the job is done.