Professor Peter Lipton: Razor-sharp Cambridge University philosopher of science

Peter Lipton, philosopher and historian of science: born New York 9 October 1954; Assistant Research Professor, Clark University, Massachusetts 1982-85; Assistant Professor, Williams College, Massachusetts 1985-91; University Assistant Lecturer, Department of History and Philosophy of Science, Cambridge University 1991-94, University Lecturer1994-97, Hans Rausing Professor of the History and Philosophy of Science 1997-2007; Fellow, King's College, Cambridge 1994-2007; married 1984 Diana Warner (two sons); died Cambridge 26 November 2007

In 1997 Peter Lipton became the first holder of the established Chair in the History and Philosophy of Science at Cambridge University. He headed the department for more than a decade, consolidating and augmenting its reputation as the leading centre for the history and philosophy of science in Britain and possibly the world. He was a supremely gifted teacher of philosophy and a university administrator with the lightest and most efficient of touches.

His most influential published work on the philosophy of science is to be found in his book Inference to the Best Explanation (1991) choosing the hypothesis that would, if true, best explain the relevant evidence. Exploring this idea, Lipton put forward original ideas on causal and contrastive explanation, proposed analysing "best explanation" as "explanation that most increases our understanding", and defended the idea that a theory deserves more inductive credit when data are predicted than when they are accommodated. Typical of his endearing style, as a man and a philosopher, was his distinction between the most likely explanation the most warranted and the loveliest which provides the most understanding. "Likeliness speaks of truth; loveliness of potential understanding."

In his book and elsewhere, Lipton used his account of inference to the best explanation to defend scientific realism in innovative and ingenious ways. He collaborated with his historian and philosopher colleagues in a major reassessment of testimonial knowledge, following the publication in 1998 of his own paper "The Epistemology of Testimony" in the journal Studies in the History and Philosophy of Science. He also made significant contributions to the philosophy of religion, philosophy of mind, freedom of the will, laws of nature, causation in the law, and to bioethics, writing the report Pharmacogenetics: ethical issues (2003) for the Nuffield Council.

Born to German-Jewish refugees in New York in 1953, Lipton attended the city's Ethical Culture Fieldston School, the renowned "haven for Jewish atheists", followed by Wesleyan University, Connecticut. He then went to New College, Oxford, where he studied physics and philosophy, working with A.J. Ayer, and met his wife, Diana Warner. Following the successful completion of his DPhil in 1985, he taught at Williams College, Williamstown, in Massachusetts, where his two sons Jacob and Jonah were born.

In 1991 Lipton accepted the lowly, non-tenured position of Assistant Lectureship in the Department of History and Philosophy of Science at Cambridge; the Appointments Committee could not believe their luck. Within five years he was Head of Department, a position he held until his death. At the age of 42, in 1997, he became Professor of the History and Philosophy of Science the chair was established through the generosity of the Rausing family. Under his wing, the Department of History and Philosophy of Science flourished and grew in size and in reputation, not least as perhaps the best-run and most cheerful department in the university.

As a philosopher, Lipton was razor-sharp and never aggressive. Unfailingly courteous to all, he would be uncannily predictable in going unerringly for the crux of an argument, always trying to find whether it was strong enough, could be improved or should be discarded. Always more light, never any heat this was the example Lipton offered. To lose an argument to Peter Lipton nearly always gave pleasure, never a sense of loss or wounding: seemingly effortlessly, he made all philosophical discussion become a collaboration in which the only winners were reason and truth. There were no losers.

In Cambridge the "Epistemology Reading Group" he organised modelled on Ayer's Oxford discussion circle was the philosophical centre of gravity in the department, a key element in the massive revivification of philosophy of science, both locally and internationally, attributable to Lipton and his influence.

Lipton always taught more than any of his colleagues, despite his heavy administrative commitments throughout the university and in King's College, where he was elected a Fellow in 1994, and was supremely successful in nurturing doctoral students. Nearly all of them bear the Lipton distinguishing marks of analytic precision and intellectual generosity.

He was just as active outside the university, talking in schools, to diverse non-specialist audiences, and as a pillar of the Jewish community in Cambridge, something he shared with his wife. He was always willing to engage with any audience about religion, about the meaning of life, about quandaries on the "Ask Philosophers" website. Asked the question: "Is time more fundamental than space, because one can go back and forward in time through memory?", he replied: "One can think about different times, but one can also think about different places; and although one can not choose when to be, one can choose where to go."

Peter Lipton drew the best from everyone. He never took advantage of a position of power; he would perceive weakness and vulnerability very quickly and then go out of his way to make such individuals feel entirely at ease. His objective virtues objective because everyone said the same of him - were his clarity of thought, the generosity pervading all his human relations, and his extraordinary warmth. The palpable love others felt from him often led them to respond in kind.

John Forrester