I was President of the Royal College of Pathologists (1990-1993); Biological Secretary of the Royal Society (1993-1998); and Founder President of the UK Academy of Medical Sciences (1998-2002); and served on UNESCO's International Bioethics Committee (1993-1998). In these capacities I became involved in the ethical and policy controversies surrounding vaccination, stem cells, transmissible spongiform encephalopathies and genetically modified food crops.