In the second world war Clive worked in military intelligence in the Royal Air Force and came into conflict with “Bomber” Harris over the policy of bombing civilian targets. He joined the Imperial Cancer Research Fund in 1946 and the Public Health Laboratory in 1949 as a microbiologist. He was a major contributor to work that led to the award of bacterial genetics pioneer Joshua Lederberg's Nobel prize in 1958. He was among the first to realise that many problems in microbiology and epidemiology could be solved only through advanced mathematical methods, and in 1962 he was appointed chief medical statistician to the registrar general. In 1979 he became a research fellow at the University of Exeter. Clive was twice married and leaves both wives; three children; and five grandchildren.