*Budapest, Pázmány P. sétány 1/A*

** 1999. Szeptember 27.** (hétfő
!)

*Rutgers University*
*Collegium
Budapest*

*Probability and Determinism*

Although probability is essential to the formulation (and evaluation)
of scientific theories and although a great deal is known about how to
employ probabilistic concepts, there is still philosophical controversy
concerning the nature of probability. Some hold that only probability concerns
only degrees of belief (either subjective or constrained by "objective"
rules) while others hold that it concerns mind-independent features of
reality. The latter view divides among those who hold that it concerns
only frequencies (actual or hypothetical) and those who hold that it concerns
a "causal propensity." The nature of probability is especially puzzling
when the underlying dynamics is completely deterministic as in classical
mechanics and Bohm's version of quantum mechanics. Some claim that when
the dynamics is deterministic then all objective probabilities are 1 or
0. But this seems at odd with the scientific practice. In my talk I will
review some of the main ideas concerning the nature of probability and
also an idea suggested by David Lewis. According to Lewis probability concerns
an objective feature of reality that supervenes on the totality of propositions
not concerning chance. Whether or not Lewis' account is correct for dynamical
chances I argue that it provides a good account of chance statements when
the dynamics are deterministic.

A szeminárium szervezője:
*Szabó
E. László*