I have been fortunate to learn from individuals too numerous to mention; but here are some, all deceased, whom I count among those to guide my thinking in particularly pronounced ways.

A.E. Cohen, 1913-2004

My father’s Ph.D. thesis, on a medieval subject, was the last one still supervised by Johan Huizinga (1941). From 1945 to 1960 my father was a researcher at the Dutch Institute for Research of the Second World War; from 1960 to 1979 he was a professor of medieval history at Leiden University. From him I learned what history is, and what it means to write about it.

Jacques de Kadt, 1897-1988

De Kadt was a most unconventional politician, who was very early in spotting the totalitarian-imperialist nature of Stalinism and of national socialism, both of which he analyzed critically in two path-breaking books in Dutch (published in 1935 and in 1939, respectively). He was also an early defender of something he called cultural socialism. My regular, friendly conversations with him stimulated me to take a broad look at things, and to think analytically about big problems.

Dick van Arkel, 1925-2010

My thesis supervisor taught me how sensible it is to approach the writing of history in an analytical and comparative way, with special care given to the proper handling of concepts.

The Drawing of the Mark of Cain. A Socio-historical Analysis of the Growth of Anti-Jewish Stereotypes. Amsterdam UP, 2009.

R. Hooykaas, 1925-1994

Deliveded in his inimitably incisive manner, Hooykaas’ lectures taught me that history of science is fully history. My subsequent friendship with him demonstrated to me that considerable cultural divergences need not stand in the way of mutual understanding and appreciation.

• ‘Eloge: Reijer Hooykaas, 1 August 1906 – 4 January 1994’. Isis 89, 1, March 1998; 181-184.
• ‘Editors’ Foreword’ en ‘Index’ van R. Hooykaas, Fact, Faith and Fiction in the Development of Science. Dordrecht: Kluwer, 1999; p. ix-xiii en 435-454.
• (with Nancy Nersessian and Christiaan Boudri:) ‘In Süssmayer’s Spirit: On the Practice of Editing in Two Distinct Cases’

Richard S. Westfall, 1924-1996

I first met Sam in 1985, at the International History and Philosophy of Science conference meeting in Berkeley. Then already he was my favorite historian of science, and ever since he passed away I cannot complete a piece of work without hoping that it would have found favor with him. I was, and am, proud to have become his friend, and I dedicated my Dutch book Isaac Newton en het ware weten to his memory.

Rob Wentholt, 1924-2010

Rob was not just one of my best friends, but also the sharpest and most versatile thinker I have met. He was an exemplar of independent thought and analytical acumen. I feel greatly honored to have been able to edit his posthumous masterpiece ‘The Nature of Human Nature’, and now to seek to get it properly published.