Bas van Fraassen


Bastiaan Cornelis van Fraassen is a Dutch-American philosopher noted for his seminal contributions to philosophy of science and epistemology. He is a Distinguished Professor of Philosophy at San Francisco State University and the McCosh Professor of Philosophy Emeritus at Princeton University.

Biography and career

Van Fraassen was born in the German-occupied Netherlands on 5 April 1941. His father, a steam fitter, was forced by the Nazis to work in a factory in Hamburg. After the war, the family reunited and, in 1956, emigrated to Edmonton, in western Canada.
Van Fraassen earned his B.A. from the University of Alberta and his M.A. and Ph.D. from the University of Pittsburgh. He previously taught at Yale University, the University of Southern California, the University of Toronto and, from 1982 to 2008, at Princeton University, where he is now emeritus. At San Francisco State University, he teaches courses in the philosophy of science, philosophical logic and the role of models in scientific practice.
Van Fraassen is an adult convert to the Roman Catholic Church and is one of the founders of the Kira Institute. He is a fellow of the American Academy of Arts and Sciences; an overseas member of the Royal Netherlands Academy of Arts and Sciences since 1995; and a member of the International Academy of Philosophy of Science. In 1986, van Fraassen received the Lakatos Award for his contributions to the philosophy of science and, in 2012, the Philosophy of Science Association's inaugural Hempel Award for lifetime achievement in philosophy of science.
Among his many students are the philosophers Elisabeth Lloyd at Indiana University, Anja Jauernig at New York University, and Professor of Mathematics Jukka Keranen at UCLA.

Philosophical work

Philosophy of science

Van Fraassen coined the term "constructive empiricism" in his 1980 book The Scientific Image, in which he argued for agnosticism about the reality of unobservable entities. That book was "widely credited with rehabilitating scientific anti-realism." According to the Stanford Encyclopedia of Philosophy:
In his essay "The Anti-Realist Epistemology of van Fraassen's The Scientific Image", Paul M. Churchland, one of van Fraassen's critics, contrasted van Fraassen's idea of unobservable phenomena with the idea of merely phenomena.
In his 1989 book Laws and Symmetry, van Fraassen, attempted to lay the ground-work for explaining physical phenomena without assuming that such phenomena are caused by rules or laws which can be said to cause or govern their behavior. Focusing on the problem of underdetermination, he argued for the possibility that theories could have empirical equivalence but differ in their ontological commitments. He rejects the notion that the aim of science is to produce an account of the physical world that is literally true and instead maintains that its aim is to produce theories that are empirically adequate. Van Fraassen has also studied the philosophy of quantum mechanics, philosophical logic, and Bayesian epistemology.

Philosophical logic

Van Fraassen has been the editor of the Journal of Philosophical Logic and co-editor of the Journal of Symbolic Logic.
In his paper "Singular Terms, Truth-value Gaps, and Free Logic", van Fraassen opens with a very brief introduction of the problem of non-referring names.
Instead of any unique formalization, though, he simply adjusts the axioms of a standard predicate logic such as that found in Willard Van Orman Quine's Methods of Logic. Instead of an axiom like he uses ; this will naturally be true if the existential claim of the antecedent is false. If a name fails to refer, then an atomic sentence containing it, that is not an identity statement, can be assigned a truth value arbitrarily. Free logic is proved to be complete under this interpretation.
He indicates that, however, he sees no good reason to call statements which employ them either true or false. Some have attempted to solve this problem by means of many-valued logics; van Fraassen offers in their stead the use of supervaluations. Questions of completeness change when supervaluations are admitted, since they allow for valid arguments that do not correspond to logically true conditionals.
His paper "Facts and tautological entailment" is now regarded as the beginning of truth-maker semantics.

Bayesian epistemology

In Bayesian epistemology, van Fraassen proposed what is now known as van Fraassen's reflection principle: "to satisfy the principle, the agent's present subjective probability for proposition A, on the supposition that his subjective propability for this proposition will equal r at some later time, must equal this same number r".

Books