Okay, in the introduction, they refers to Muslims as "Mohammedans", this should give you some idea of roughly how old this book is. Still, this book is all the more incredible for it. This was published at an age before religious "tolerance" was politically correct, for the sole reason that the author felt that a grasp of religion is incomplete if you feel only one religion is the one for you (and it proceeded to point out the individual faults of each main religion), and only by learning from the strengths of each can one become better at one's patron faith.Plus, they included Taoism and Zen Buddhism on the list, which typically gets blown off as minor faiths. All in all, a very fine book for my dad, a retired priest.