 Laudan (1984) agreed with Kuhn that the goals, standards, and methods of science change historically as well as the theoretical and observational claims, but his “reticulationist model” rejected as historically inaccurate Kuhn’s claim that sometimes they all change together to constitute a (Kuhnian) revolution. Dramatic change in one place need not seriously disturb fixity elsewhere and rarely or never does. Hence, incommensurability is a pseudo-problem. Moreover, Laudan contended, his reticulationist model overcomes the hierarchical problem that has led thinkers such as Poincaré and Popper to make the goals of science arbitrary (the top of the hierarchy and hence the unjustified justifier of what comes below), e.g., mere conventions. These authors have no way to rationally appraise the goals themselves, leaving their positions stuck with an account of merely instrumental reason: efficiency relative to a given, arbitrary goal. By contrast, in Laudan’s model, the elements are mutually constraining, mutually adjusting, an idea prominent in Dewey’s attack on hierarchy in his 1939. None takes absolute precedence over the others. Thus, some goals are irrational because present and foreseeable knowledge and methods have no way to achieve them or to measure progress toward them. (Laudan thereby rejected strong realist goals as irrational.) An advance in substantive or methodological expertise can make it rational to embrace new standards and also new goals.