ABSTRACT
This chapter discusses a number of related doctrines collected under the head of "constructivism" and presents the view that incommensurability is a problem of language rather than metaphysics. It considers the idea that Kuhn is a nominalist about high-level natural kinds and also discusses an argument for conceptual relativism. The chapter also considers the thesis that theories deal with different worlds because of the theory-dependence of observation and the relativity of objects. Theories impose different orderings on the supra-empirical world: since there is no way to check those orderings against real categories, the kinds posited by theories are the only higher order kinds of any significance to us. Objects can only be dealt with, for cognitive purposes, once they are brought under descriptions. But described objects must be described in terms of some conceptual framework. In neither case do the objects studied in science depend for their existence on particular theories.
