His outlook has been forged by the experience of a family in permanent exile. His Jewish grandfather's forced emigration from Austria following Hitler's Anschluss in 1938 was followed 10 years later by his father having to flee his native Honduras after having fallen foul of the dictatorship which had come to power. By 1971, when Professor Moncada decided to quit Central America in disgust over the regime then terrorising his adopted El Salvador, he was following in a long family tradition.
But alongside this zeal to better the lot of his fellow man has burnt an equally strong desire to push out the frontiers of medical science. It is the triumph of that latter ambition which in the 1980s led Professor Moncada, while working at Wellcome, to the discovery of prostacyclin, a substance which stops blood clotting, and later to reveal the crucial importance of nitric oxide to the body's functioning. Former colleagues say that work brought him to within an ace of winning a Nobel prize. That same drive is now spurring him to establish the Cruciform Project, a ground- breaking attempt to set up a multi-disciplinary medical research facility bridging the gap between academia and industry.
For the past nine months, Professor Moncada and a team of 60 research scientists have set themselves up to unlock the secrets of some of the Western world's biggest killers. The research will concentrate on arteriosclerosis - heart attacks, strokes and the like; neuronal damage and repair - dealing with the after-effects of conditions such as stroke and Alzheimer's disease; and cancer.
But while millions of pounds are being thrown at similar research across the globe, the novelty of Professor Moncada's approach is the all-embracing nature of this new attack. Instead of being divided up into small teams, narrowly focused on specific disease areas, the Cruciform project will involve a large team of many disciplines working together using basic molecular science to achieve a common aim. The new institute, yet to be given a name, has attracted senior figures from both clinical science, such as Professor John Martin of the British Heart Foundation, and industry, including Professor Moncada's deputy, Ken Powell, formerly of Wellcome. Some 25 people from Wellcome's now-defunct research base at Beckenham in Kent have moved over to join Professor Moncada.
The significance of all this will not be lost on Britain's latest Nobel laureate, Sir Harold Croto, who warned this month that the low level of state funding meant research into basic science was "now below its survival threshold". The Government, he claimed, was using coercion to force scientists like him to work with industry.
The contrast with Professor Moncada's approach is stark. He has harnessed Government and industry in backing an institute dedicated to basic science. That has already won him pledges of support totalling pounds 26m from Government and the Wellcome Trust for the pounds 41.5m capital cost of converting the eponymous Cruciform building of the old University College Hospital in London. On top of that, the drugs industry and academic sources have promised pounds 2.5m of the expected pounds 12m to pounds 14m running costs when the institute opens in the autumn of 1998 with a staff of some 300.
Glaxo Wellcome, the drugs giant which last year subsumed Professor Moncada's former employer, is committing itself to pounds 10m over seven years to pursue research into the effect on septic shock of nitric oxide, the area which Professor Moncada pioneered as head of Wellcome's research efforts in the 1980s. Glaxo Wellcome will keep the intellectual property rights, with the Moncada institute receiving royalties from any new drugs which result from the work.
Outsiders suggest there is the prospect for a whole series of similar deals. Rolf Stahel, another member of the Wellcome diaspora, who is now chief executive of biotech group Shire Pharmaceuticals, says his group and Professor Moncada's are "beautifully complementary".
Shire will be looking hard at fundamental work carried out at the institute in areas such as the central nervous system for potential development prospects. But there will be no millionaire boffins a la British Biotech from new blockbuster cures based on work coming from UCL. The majority of the royalties will be ploughed back into what Professor Moncada emphasises will be basic science. "We are going to do fundamental research as the main point of our activity. I think what we are doing is exploiting the interface between academia and industry," he says.
In the first instance, this will be to apply discoveries in a more efficient way and secondly to fund further fundamental research. "One of the problems [of this country] has been the slow transfer of scientific knowledge into practical applications. That is one of the gaps we want to bridge," he says.
Professor Moncada sees a growing need for a basic research body of this sort, given the trend towards consolidation in the drugs industry. "I think the pressures from the market are forcing the industry to concentrate on development rather than research. My feeling is the drugs industry will rely more and more on academic research and smaller, start-up companies. They will be more efficient and more productive."
But he differentiates Cruciform from biotechnology companies such as British Biotech and Shire. The emphasis of the science used by such companies is on large-scale molecular biology, he says, using proteins and peptides. By contrast, his institute will use smaller molecules and concentrate on how they affect chemical processes, rather than creating drugs or cures for diseases.
It is a noble enterprise, at least as worthy as his attempts to aid his fellow countrymen in Central America, and one that would present a challenge to a young person, let alone a man of 51. But Professor Moncada is used to radical departures, having had literal experience of them in his flights from various dictatorships.
On past form, he will scale this new peak with ease, potentially giving London a new centre of excellence in medicine, not just in research, but in teaching too. The institute should be up and running in time for the planned merger of London's Royal Free, Middlesex and University College medical schools. After that, who knows.
"I have never made long-term plans, although I have done things for a long time," he says. "I have been a scientist for a quarter of a century. I would like to believe that I still will have the flexibility to look for the excitement and go for it, rather than settling."