Reijer Hooykaas was born on 1 August 1906 in Schoonhoven, the Netherlands. A pioneer in the history of science, he was the first to hold a chair in the discipline at a Dutch university. In 1945, Hooykaas was Professor of the History of Science at the Free University of Amsterdam, also teaching mineralogy from 1948 to 1960 and instrumental in establishing the collection. He later moved to the University of Utrecht as Professor of the History of Science, retiring in 1976. For many years, Hooykaas was active in the Christian Society of Scientists and Physicians in the Netherlands.
Member of the Royal Netherlands Academy of Arts and Sciences in 1959, he was President of the International Commission of the History of Geological Sciences from 1976 to 1984. He often spoke at Christians in Science conferences in the UK and gave the Erasmus Lectures at Harvard in 1975. Important works include Natural Law and Divine Miracle (1963), ‘Catastrophism in Geology’, Nieuwe Reeks, 33 (1971), Religion and the Rise of Modern Science (1972), and ‘The Rise of Modern Science: When and Why?’, British Journal for the History of Science 20 (1987).