David's father, Alfred Clark, was professor of pharmacology at University College London from a Quaker background and expected his son to follow in his footsteps.
After a spell in Sumatra where he organized the evacuation of 20,000 Dutch civilians from a Japanese internment camp, he spent six months in Palestine where he had his first experience of psychiatry.
[1] He then trained under Sir David Henderson in Edinburgh and Professor Aubrey Lewis at the Maudsley, before being appointed in 1953 at age 32 to Fulbourn Hospital as the youngest medical superintendent in the country, responsible for nearly 1,000 patients.
In 1962 he made a trip to the USA visiting David A. Hamburg at the Center for Advanced Study in the Behavioral Sciences, located as a institute at Stanford independent from the University.
[3] His verdict on recent changes in the NHS was critical: "Authoritarian, bureaucratic organisation which the NHS has become... run by managers under constant pressure from central government to save money, cut costs and keep things under tight control... they have reverted to the kind of administrative behaviour that marked the worst of the asylum days.