On Johnson's Paradox: Hypothesis Verification

Abstract

When H. M. Johnson argued that all inductive reasoning is based on the fallacy of affirming the consequent and cannot therefore establish the 'truth' of scientific hypotheses, he posed paradox for strict empiricists. Not so for theoreticians, however, because it does not follow from the fact that partial inference has the form of this deductive fallacy that the entire abductive process is fallacious. The problem of hypothesis formation is distinct from that of hypothesis confirmation, and Johnson discussed only the latter. From larger, theoretical point of view, it is valid to derive deduction from the inductive generalizations of conceptual model and to apply it hypothetically to an empirical situation. That is justified epistemologically by the success with which the entire hypothetical proposition orders set of natural phenomena. Webster defines paradox as a statement that is seemingly contradictory or opposed to common sense and yet is perhaps true. And Gilbert and Sullivan have their pirates sing How quaint the ways of Paradox, / at common sense she gaily mocks! By 'Johnson's paradox' I refer to the position the late Harry Miles Johnson took in his penultimate publication in this journal about the fallacy of affirming the consequent. The paradigmatic empirical situation he sketched, with his customary elegance and clarity, was one in which any or all implicates (I) are materially implied by some hypothesis (H) whose factual status is undetermined but