A logic that allows no evidence against a contingent statement fails to measure the extent to which premises indicate the likely truth-values of conclusions.
One important respect in which inductive logic should follow the deductive paradigm is that the logic should not presuppose the truth of contingent statements. If a statement C is contingent, then some other statements should be able to count as evidence against C. Otherwise, a support function \(P_{\alpha}\) will take C and all of its logical consequences to be supported to degree 1 by all possible evidence claims. This is no way for an inductive logic to behave. The whole idea of inductive log