The higher synthesis known as Theosophy at least does not exclude Catholics.

Theosophy is not a higher synthesis. It is an anti-Christian confusion of philosophical remnants. And whether it excludes Catholic adherents or not, the Catholic Church excludes Theosophy, prohibiting its doctrines as being utterly irreconcilable with the teachings of Christ. The doctrines were well weighed before the Church issued the decree of 1919, and that decree will never be withdrawn. By it the Catholic Church showed once more how conscious she is of her duty to preserve the exact doctrine of Christ just as He gave it to mankind.

Radio Replies Volume 1 by Rev. Dr. Leslie Rumble MSC and Rev. Charles Mortimer Carty