Bas van Fraassen was born in Goes, the Netherlands, on April 4, 1941, and with his family, emigrated to Canada in 1956. Bas received his B.A. in philosophy from the University of Alberta in 1963. He went on to do graduate work in philosophy at the University of Pittsburgh, where he received his M.A. in 1964 and his Ph.D. in 1966, writing a dissertation on the causal theory of time under the direction of Adolph Grünbaum. After graduating from Pittsburgh, Bas was offered a position in the philosophy department at Princeton, but turned it down in favor of an offer from Yale, where he taught from 1966 to 1969. He also taught at the University of Toronto (1973–81), and the University of Southern California (1976–81) before finally joining the faculty at Princeton, first as a visiting professor in 1981, and then in 1982 as a professor. In 1998 Bas was named the McCosh Professor of Philosophy.

Bas is one of the most prolific philosophers in the profession, and has contributed to a wide variety of areas. He has written and published a dazzling number of important books and articles in philosophical logic, probability theory and epistemology, metaphysics, philosophy of art and literature, and philosophy of religion, in addition to work that doesn’t neatly fit into one category or another. But Bas’s main work, the work that brought him international recognition, is a series of books and articles in the philosophy of science.

At the center of this work is his seminal book, The Scientific Image (Oxford, 1980). In this book, Bas argues for a bold position in the philosophy of science that he calls “constructive empiricism.” According to constructive empiricism, “science aims to give us theories which are empirically adequate; and acceptance of a theory involves as belief only that it is empirically adequate,” where a theory is empircally adequate, roughly speaking, “if what it says about the observable things and events in this world, is true—exactly if it ‘saves the phenomena.’” Though Bas does not want to deny that scientific theories are literally true or false, he wants to argue that the aim of science is not to establish theories that are true or false in the realistic sense, but only theories that make a difference in a way that can matter to us, that is to say, in what it is that we can actually observe. (In The Scientific Image, Bas also introduced the widely discussed and widely adopted semantic view of scientific theories, on which theories are to be identified not with a set of sentences or theorems in an axiomatized system, but with a collection of models, the set of structures which satisfy the axioms.) In his later books he extends his view to some specific do- mains in the philosophy of science, to the question of physical laws in the world [Laws and Symmetry (Oxford, 1989)] and to quantum mechanics [Quantum Mechanics: An Empiricist View (Oxford, 1991)].

More recently he reiterated and further developed his views in his Terry Lectures at Yale University, published as The Empirical Stance (Yale, 2002). Readers now await the appearance of his latest book, again extending these themes to new domains, Scientific Representation: Paradoxes of Perspective (Oxford, 2008).

Bas’s constructive empiricism is a bold and surprising view to articulate and defend, and he does so with courage, imagination, and some very ingenious arguments. While it may not have been widely accepted, the view has been widely discussed and debated among philosophers. The Scientific Image won the Franklin J. Matchette Prize of the American Philosophical Association in 1982 and the Imre Lakatos Award in 1986. But more than that, it was the target of numerous articles, conferences, and collective volumes, discussing Bas’s unorthodox position at great length. In this way, Bas has made a lasting contribution to philosophy. Like positions taken by some of his great predecessors among empiricist thinkers, such as George Berkeley’s reduction of body to sensory perceptions or Hume’s denial of the rationality of causal inference, Bas has taken an initially implausible position and shown just how far it can be developed in a systematic, coherent, and even convincing way. And like Berkeley or Hume, he has forced his opponents to address the surprisingly difficult task of articulating and defending alternatives to his view.