 Some philosophers (e.g., Loar 1981; McGinn 1982; Block 1986) objected to the reduction of lexical meaning to reference, or to non-psychological factors that are alleged to determine reference. In their view, there are two aspects of meaning (more generally, of content): the narrow aspect, that captures the intuition that ‘water’ has the same meaning in both Earthian and Twin-Earthian English, and the wide aspect, that captures the externalist intuition that ‘water’ picks out different substances in the two worlds. The wide notion is required to account for the difference in reference between English and Twin-English ‘water’; the narrow notion is needed, first and foremost, to account for the relation between a subject’s beliefs and her behavior. The idea is that how an object of reference is described (not just which object one refers to) can make a difference in determining behavior. Oedipus married Jocasta because he thought he was marrying the queen of Thebes, not his mother, though as a matter of fact Jocasta was his mother. This applies to words of all categories: someone may believe that water quenches thirst without believing that H2O does; Lois Lane believed that Superman was a superhero but she definitely did not believe the same of her colleague Clark Kent, so she behaved one way to the man she identified as Superman and another way to the man she identified as Clark Kent (though they were the same man). Theorists that countenance these two components of meaning and content usually identify the narrow aspect with the inferential or conceptual role of an expression e, i.e., with the aspect of e that contributes to determine the inferential relations between sentences containing an occurrence of e and other sentences. Crucially, the two aspects are independent: neither determines the other. The stress on the independence of the two factors also characterizes more recent versions of so-called “dual aspect” theories, such as Chalmers (1996, 2002).