Deduction, induction and probabilistic support

James Cussens

pp. 1-10

in: Synthese 108 (1), 1996.

Abstract

Elementary results concerning the connections between deductive relations and probabilistic support are given. These are used to show that Popper-Miller's result is a special case of a more general result, and that their result is not “very unexpected” as claimed. According to Popper-Miller, a purely inductively supports b only if they are “deductively independent” — but this means that ⌝ a ⊢ b. Hence, it is argued that viewing induction as occurring only in the absence of deductive relations, as Popper-Miller sometimes do, is untenable. Finally, it is shown that Popper-Miller's claim that deductive relations determine probabilistic support is untrue. In general, probabilistic support can vary greatly with fixed deductive relations as determined by the relevant Lindenbaum algebra.

Cited authors

Popper Karl