Abstract
With few exceptions, theorists analyze group attitudes in terms of the attitudes of members. In Epstein 2015, 2019a, 2019b, I argued that this thesis (which I call "MEMBERS ONLY")—and hence any theory that analyzes group attitudes in terms of member attitudes—is mistaken: the attitudes of many groups are ontologically determined by a broader range of factors than member attitudes. My aim in the present paper is to consider new arguments against MEMBERS ONLY. I argue that arguments based on the "hypothesis of the extended mind" are not persuasive for challenging MEMBERS ONLY, but reinforce my earlier arguments, and I also propose new arguments from group content externalism are more promising.