[kieckerjan]

I agree that the impact on philosophy was probably far greater than on science and math, but the fact is that several prominent mathematicians (most notably Gödel) were part of the group. One can of course argue whether e.g. Gödels achievements had anything to do with his being a member.

As to your second remark, I did not mean to imply that the people listed were all members. They were not. But they did have affiliations with members of the group (personal and professional) and they are all discussed in the book.