 As Jerrold Katz (1988) emphasized, this second definition is significantly different from the “containment” idea, since now, in its appeal to the powerful method of proof by contradiction, the analytic would include all of the (potentially infinite) deductive consequences of a particular claim, many of which could not be plausibly regarded as “contained” in the concept expressed in the claim. For starters, Bachelors are unmarried or the moon is blue is a logical consequence of Bachelors are unmarried—its denial contradicts the latter (a denial of a disjunction is a denial of each disjunct)—but clearly nothing about the color of the moon is remotely “contained in” the concept bachelor. To avoid such consequences, Katz (e.g., 1972, 1988) went on to try to develop a serious theory based upon only the initial containment idea, as, along different lines, does Paul Pietroski (2005, 2018).