I'm being a bit harsh giving this 3 stars because it is a really good book and everyone should read it. But there are inherent flaws on Iain's arguments that I cannot come to terms with. The first being that he treats the Right Brain as superior to the Left brain (the master and the emissary), which in itself is a hierarchical (left brain) way of thinking. Second, the author doesn't realize that religion is mostly left brain oriented. The inability of the left hemisphere to deal with uncertainty is the cause of all this God, karma, reincarnation hypothesis. The third and most important is the fact that the author doesn't warn about the right-brain impulsivities that plague most of the Eastern world. The herd mentality, the lack of individualism, the lack of introspection, the lack of proactiveness are all causes of a dominant right-hemisphere suppressing the left brain. And anyone who's lived in an eastern country (or even a small village) would immediately realize this.
So rather than giving the high-ground to one hemisphere, this book would've been so much better if it was balanced. Rather than a Master and an Emissary, it would've retained it's scientific touch (which it does so brilliantly in the first few chapters) if the story was about two masters, struggling, co-existing and co-inhabiting the brain.