In my younger days, decades upon decades ago, we were consumed by the threat of nuclear annihilation. The forces of darkness, East and West, seemed in the ascendance. The Doomsday clock inched its way to midnight.

And then there arose, across a spectrum ranging from the scientists and engineers writing in the Bulletin of Atomic Scientists, through to the Physicians for the Prevention of Nuclear War, a loud clamouring cry of protest, accompanied by marches, banners, polemics, statements, press conferences demanding, in the name of humankind, that the madness end.

And it did, at least for a time at the end of the Cold War. And the scientists and doctors won Nobel Peace Prizes and showed the power of scholarly activism for the whole world to see.

Two weeks ago, just prior to the meeting of the G8, a full-page ad appeared in the Financial Times, with the headline "Scientists Call on World Leaders to Take Action on Climate Change".

It was signed by twenty-five of the most renowned climatologists and earth scientists. They didn't get all they wanted by any means, but they jolted the political leadership into the recognition that the scientists are mobilized, are watching, are keeping the rest of the world informed and will not be silenced.

I was immediately reminded of the letter, signed by eighty-one acclaimed medical clinicians and researchers right after the Toronto AIDS conference, demanding the resignation of the then

South African Minister of Health for reasons everyone in this audience understands. It was an important moment in the accelerating, cumulative pressure for a change in policy, a change now underway.

In truth, there are many in this audience who fought for that change. This is an audience that has devoted itself to making the world a better place, so I hope that what I'm about to say will comfortably resonate.

No one should underestimate the power and influence of science when it decides to take a stand.

The two co-Chairs of this Conference are striking examples, amongst many, of the extraordinary impact scientists can have. And never has the exercise of power and influence been more imperative than at this moment in the fight against the AIDS pandemic.

Your individual and collective voices are needed sure, you have the technological and laboratory acumen, you know about vaccines and microbicides and triple combination therapy and viral loads and CD4 counts and pre- and post-exposure prophylaxis the entire panoply of sophisticated scientific discovery and intervention.

And that's your work, and it's of inestimable value. We need you to unravel the secrets of the science, to make all of that elusive and mysterious information accessible to the untutored rest of us. But we need the scientific community as well to speak clearly, and unequivocally, boldly and evocatively to the power-brokers of this world, telling them of the risks and the benefits, and what will happen if they make the wrong choices.

Somehow, along with the science, we need the activism. They are inseparable.

So when, as now, there's a backlash against funding for AIDS, with mindless charges against AIDS exceptionalism, you should find a way, collectively, to shoot down the pinched bureaucrats and publicity-seeking academics who advocate exchanging the health of some for the health of others - who propose robbing Peter to pay Paul rather than arguing, in principled fashion, that money must be found for every imperative, including maternal and child health, and sexual and reproductive health, and environmental health as well as all the resources required to turn the tide of the AIDS pandemic.

It can never be an either/or. We're talking about human lives for God's sake, not about the phony parsing of balance sheets. The Treasuries of the western nations are very artful at the divide and conquer route. We must never allow them to play one part of the health sector against the other.

HIV/AIDS, for all the horrendous human consequences, has objectively strengthened health systems, has brought together all the sectors of government from agriculture to education, has integrated private and public initiatives, has exponentially raised awareness of the consequences of gender inequality, has spawned remarkably novel ideas for raising resources all of it inevitably improving human health overall.

Believe me, if we could have back the lives we've lost, I'd relinquish in a heartbeat the institutional gains that flow from AIDS. But we can't, so at least don't undervalue or dismiss the gains.

It's so easy for the detractors to coddle specious arguments. Rather than asking for more money, they have this punitive spasm to ransack resources for AIDS. You must not let them get away with it.

And when the G8 won't renew its 2005 commitment to universal access; when the G8 cynically uses the financial crisis to threaten cutbacks to AIDS funding; when the G8 once again, yet again, always again subverts its own promises and in so doing compromises the health of millions, then it's time for science to speak with one powerful voice of accusation. And when the Global Fund faces a shortfall of several billion, you would do the world a tremendous service by simply finding a way, collectively, from your positions of authority, to remind the political leadership of how they used precious public money to bail out the banks, so that Goldman Sachs could make a profit of $3.4 billion in the second quarter of 2009, JP Morgan Chase could make a profit of $2.7 billion in the same period, and with obscene contempt for the human condition, pay bonuses, yet again, beyond the dreams of hyperactive wealth.

You spend every day of your working lives to make life possible, and the power brokers devalue your work with the fraudulent plea of destitution. Don't let them get away with it.

But funding isn't the only issue; the issues proliferate. When the Government of Senegal jails eight gay AIDS activists for no reason except homophobia, setting back the fight against AIDS, where are the scientific voices of condemnation?

Right now, in the Caribbean, every country save the Bahamas, has laws that criminalize homosexuality. We tiptoe round this twisted form of racism. We submit to ridiculous claims of cultural relativism. The Prime Minister of Jamaica, in the safety of Parliament, makes the most contemptible statements about gay men, leaving every elemental component of human rights in tatters, and he's never called to account ... not by the UN Human Rights Council, not by the G8, not by the G20, not by the Commonwealth only by the gay activists themselves.

What is wrong with the international community? If this is how it behaves, it doesn't deserve the name "community" at all. And if the political leadership lacks the courage to confront such outrageous slander, you shouldn't lack the courage. You're scientists. You know that it's a scientific reality that a certain percentage of the world's people is gay. So tell the political philistines to get over it and stop wrecking such damage. More, you know that an ugly homophobic culture is a threat to public health that inevitably serves to spread the virus I beg you to say so. The majesty of science is its influence.

Then there's the issue, commonly known as PMTCT --- prevention of mother to child transmission. This should have been the easiest intervention of all, instead we've had a panorama of unnecessary death for both the mothers and their children. So-called PMTCT has been a colossal failure, subjected to twisted linguistics, lousy science, governmental chicanery, and astonishing delinquency on the part of United Nations agencies. Only now is the political establishment coming to its senses. But it needs your help so that it never goes off the rails again.

What help? Let me count the ways. First, never again should it be called mother-to-child transmission. It should better be called vertical transmission. How is it that we so casually, mindlessly demonize the mother by naming her as the vector? Second, even now a dreadful double standard prevails: in the industrial world we use full HAART; in the developing world we still use, in the majority, single-dose nevirapine.

You're scientists: you know what that means in terms of unnecessary infant infection and death. Third, we abandon the mothers. In 2007, only 12 per cent of pregnant women living with HIV identified during antenatal care, were assessed for their eligibility to receive ARV treatment. That's an unconscionable neglect of women that smacks of vestigial misogyny. Fourth, the WHO/UNICEF/UNAIDS guidelines on breastfeeding, and the use of breast-milk substitutes are widely ignored. To this day, the value of exclusive breast-feeding for six months in stemming HIV infection and providing the infant with the strongest possible immunity to other diseases is still caught between conjecture and disavowal.

Sometimes I think that every Minister of Health should be required to take a mandatory course from Dr. Coovadia. Failing that, the UN, and primarily UNICEF, should do its job, and mount a massive global education campaign to replace myths with facts about infant feeding. Political and cultural influences can be dead wrong where infant feeding is concerned; the scientists here assembled have an indispensable role to play in setting the world straight.

And there's one other matter I must raise. The epidemic of domestic sexual violence that lacerates the soul of South Africa is mirrored in the pattern of grotesque raping in areas of outright conflict from Darfur to the Democratic Republic of the Congo, and in areas of contested electoral turbulence from Kenya to Zimbabwe. Inevitably, a certain percentage of the rapes transmits the virus. We don't know how high that percentage is. We know only that women are subjected to the most dreadful double jeopardy.

The point must also be made that there's no such thing as the enjoyment of good health for women who live in constant fear of rape. Countless strong women survive the sexual assaults that occur in the millions every year, but every rape leaves a scar; no one ever fully heals.

This business of discrimination against and oppression of women is the world's most poisonous curse. Nowhere is it felt with greater catastrophic force than in the AIDS pandemic. This audience knows the statistics full well: you've chronicled them, you've measured them, the epidemiologists amongst you have disaggregated them. What has to happen, with one unified voice, is that the scientific community tells the political community that it must understand one incontrovertible fact of health: bringing an end to sexual violence is a vital component in bringing an end to AIDS. The brave groups of women who dare to speak up on the ground, in country after country, should not have to wage this fight in despairing and lonely isolation.

They should hear the voices of scientific thunder. You understand the connections between violence against women and vulnerability to the virus. No one can challenge your understanding. Use it, I beg you, use it.

When I said at the outset that this was the most critical moment, I wasn't indulging in rhetorical flourish. As has been pointed out time and time again, 2010 is the anointed year for universal access. We have but seventeen short months. If ever the scientific community was to engage in public activism, that time is now. Not only must we save every life we can in that seventeen months, but we have to create such energy that the tide of intervention is irreversible, and neither financial downturns nor the feckless caterwauling of the critics of AIDS funding will compromise our goal.

Make no mistake about it: that means taking on the development aristocracy and those who advise and influence it for example, DfID in the United Kingdom, and the World Bank and the IMF and even the World Health Organization.

Pause for a moment to think what we're dealing with. AIDS exceptionalism is a perfectly defensible and descriptive concept. Why do you think the world created an organization called UNAIDS? AIDS was exceptional. AIDS is exceptional. I tramped the high-prevalence countries of Africa for more than five years; if I wasn't viewing the most exceptional communicable disease assault of the twentieth century, then the word "exceptional" needs to be re-defined.

As a consequence of that exceptionality, and the tremendous campaigning of grass-roots advocates, AIDS received funding, a lot of funding never enough to be sure, but enough to recognize the exceptionality.

Then along come the detractors, driven by resentment, resentment at the success of the AIDS movement. These arithmetic arguments alleging that AIDS is getting too much money at the expense of other health imperatives this is simply naked academic and bureaucratic envy. I know I'm not supposed to say that, but it's got to be said.

Why? Because the critics know that it's not a matter of pitting one aspect of health against another. The critics know that it's a matter of measuring the resource needs of global health against the crazy expenditures that the world makes on other things. But the seething resentment that pulsates beneath the surface creates this false argument.

I urge the scientists and activists here assembled not to fight on the terrain of the poseurs. Your whole life is in the world of AIDS. You know the legitimate resource requirements. You just can't permit an intellectual contrivance --- an argument in favour of accepting the size of the pie and slicing it differently, rather than demanding a larger pie --- you can't allow that to be used to justify a terrible reversal in public policy. People infected with HIV or at risk of infection, are suddenly tossed onto the landscape of treatment ambiguity, and the gains we've made and the momentum we've achieved are put at risk.

Is my naiveté showing? Why is it not possible to allocate sufficient money for every aspect of global health, of which AIDS is but a part, and in so doing, meet the Millennium Development Goals money which is but a fraction, a miniscule fraction of all the public dollars that have found their way, in one short year, into the bottomless pits of greed and avarice?

No one dies from a surfeit of money. People die when poverty and disease are the twin ingredients of life.

Madiba turned ninety-one yesterday. I strolled down to the waterfront here in Cape Town where people were singing and dancing and irrepressibly celebrating the life of their national treasure.

This country has been through tough tough times. The numbers of deaths, the psychotic denialism, the political betrayals; it's taken an incredible toll. And yet, in the liberation and its aftermath, and the constitution, the law, the courts, the phenomenal culture of community activism, most sublimely exemplified by the Treatment Action Campaign in all of that, there lies hope. I saw hope everywhere yesterday. And if that tumultuous passage from despair to hope can happen here, it can happen anywhere.

But to take it to a global scale, requires the collective will of people like the people at this conference people who speak with unimpeachable scientific authority, and if they so wished, and brought advocacy to bear, could move the mountains of resistance and inertia.

You could strike a fatal blow against the pandemic. I salute those of you who have already risen to that challenge. I leave it with all of you.