"In a pre-Cartesian world, where there was as yet no clear boundary between self and other ..." (Shagan, The Rule of Moderation, 34.)
It's tossed-off notions like this that make me doubt the word of otherwise obviously intelligent and diligent scholars (especially ones who elsewhere, with due humility and good humor, announce their design to refrain from "practicing philosophy without a license").
What does the sentence mean (beyond its rhetorical function of throwing shade on an already tenebrous pre-Cartesian landscape)? It could point to the sort of clannishness that is epitomized in Romeo and Juliet, in which one's identity as Capulet is deemed to be at least as strong as one's personal desires, interests, and aspirations. But "deemed to be" is key here: the story of Romeo and Juliet is precisely about the family feud's failure to prevent strong independent desires on the part of two scions of the houses involved. Whatever the powers that be of R&J had imagined, the power of collective identity is proven to be not nearly so strong as it had been deemed to be. And whether one speaks of desires, or thoughts, or opinions, or interests, or habits, there are plenty of instances in Early Modern England alone of individual independence thereof. This was, after all, not only the era of growing European absolutism, but also the era of martyrdom. One need not base one's personal epistemology in Cartesian doubt in order to be moved to question "ethical claims [that] routinely contained and implied claims of authority and control" (ibid.).
To be wholly fair, I'm sure Shagan knows this. His book describes many instances of rebellion against the moderating actions of authority, indicating that he was fully aware of the possibility of individualizing thought. But that careless clause, taken out of context, would suggest otherwise.
Well, let it be a lesson for my own writing. Nothing does more damage to a good argument than the assumption of a broad principle that one doesn't even need picked up off-handedly from allies whose work one doesn't fully understand and presented to the wary reader whose trust one has yet to gain.