 Over time and place, the reasons Reichenbach gives for convergence of frequency estimates to a limiting value vary, including 1) his early view that convergence is synthetic a priori, or that 2) the principle of induction expresses a kind of psychological habit, 3) the semantic argument we quoted above in Section 2.2 that the negation of the principle of induction is meaningless, 4) a pragmatic vindication that induction using the straight rule works if any method of induction works, 5) a convergence argument based on higher order probabilities, or 6) that there is no guarantee, merely “posits.” 