 Mill’s theoretical philosophy is, in an important sense, circular and self-supporting (Skorupski 1989: 125, 149). As noted, Mill views enumerative induction—the sole method of warranted theoretical reasoning—as self-validating and self-improving. We spontaneously take certain initial inductive moves to be justified. Induction’s self-examination then leads to an increasing confidence that induction is a warranted way of reasoning about the world, and to a general sharpening of that method of reasoning. Induction could have been self-undermining—its success as a form of reasoning about the world, established on its own terms, is not trivial.