Evidence for the Deterministic or the Indeterministic Description? – A Critique of the Literature about Classical Dynamical Systems

It can be shown that certain kinds of classical deterministic descriptions and indeterministic descriptions are observationally equivalent. In these cases there is a choice between deterministic and indeterministic descriptions. Therefore, the question arises of which description, if any, is preferable relative to evidence. This paper looks at the main argument in the literature (by Winnie, 1998) that the deterministic description is preferable. It will be shown that this argument yields the desired conclusion relative to in principle possible observations where there are no limits, in principle, on observational accuracy. Yet relative to the currently possible observations (the kind of choice of relevance in practice), relative to the actual observations, or relative to in principle observations where there are limits, in principle, on observational accuracy the argument fails because it also applies to situations where the indeterministic description is preferable. Then the paper comments on Winnie’s (1998) analogy between his argument for the deterministic description and his argument against the prevalence of Bernoulli randomness in deterministic descriptions. It is argued that while there is indeed an analogy, it is also important to see that the arguments are disanalogous in another sense.