  Neo-Russellians are more permissive about the objects of acquaintance, including extra-mental particulars in this class. David Kaplan's pioneering work (1977/1989) is typically the starting point, although Russell himself started out with such a position, maintaining, for example, that Mont Blanc itself is a constituent of the thought that Mont Blanc has snowfields. Neo-Russellians must deny the Fregean claim that whenever misidentification is rationally possible, there is a difference in thought constituents. They might still agree with Fregean intuitions about the truth and falsity of propositional attitude ascribing sentences — agreeing, for example, that ‘Peter believes that Mark Twain was a famous American author’ is true while ‘Peter believes that Samuel Clemens was a famous American author’ is false — claiming that this does not require a difference at the level of thought constituents, following, for example, Mark Crimmins and John Perry (1989) or Mark Richard (1990). Such neo-Russellians claim that the truth or falsity of a belief attitude ascribing sentence involves more than just the agent of the report having among her beliefs the proposition expressed by the sentence embedded in the reporting sentence. Alternatively, the neo-Russellian might deny the Fregean intuitions about the truth and falsity of propositional attitude ascribing sentences, following, for example, Nathan Salmon (1986) in accounting for those intuitions in nonsemantic terms. (For further discussion, see propositional attitude reports.)  Either way, however, given that misidentification of extra-mental particulars is obviously possible, the permissive theory of acquaintance requires denying the claim that all cases of misidentification involve differences in thought constituents.