The history of Culpeper's life was quite fascinating. I was struck by how many parallels there are between the lives of Culpeper (1616-1654) and of Samuel Thomson (1769-1843), particularly in their personalities (both were arrogant, abrasive, and highly motivated) and their relationships with the conventional medical authorities of their respective days - both worked to bring medicine to the common people and drew the ire of those in the establishment. It's also noteworthy how much Culpeper accomplished and recorded in a short life.
[Tobyn's explanation of] Culpeper's [version of the Greco-Arabic] system of medicine was the real draw of this book for me, as a practicing herbalist in the Western tradition. Tobyn does a great job explaining the applicatications of humoral/tempermental theory at several levels of detail, making explicit and clear several concepts that are obscure for modern readers of Culpeper's original writings. It is gratifying to see an elucidation of the Western herbal tradition's schematic basis that conveys its intricacy and utility at a high level. Oftentimes people have an erroneous idea that, while Traditional Chinese Medicine and Ayurveda have long-standing traditions of great depth and complexity, Western herbalism is primitive or simplistic by comparison; this book is an effective counterargument.
As for the final section about Culpeper's astrological-medical concepts . . . well, I have to admit I don't understand it too much better now than when I started reading. I have only the barest prior experience with astrology, and while I could get along with some of the basics (e.g. elemental attributes of signs and planets as influences on an individual's constitution), the layers of complexity piled up quickly and I was soon out of my depth. The author eventually gives up on defining or explaining certain astrological phenomena, I assume because he just got really excited about what he was into. (I felt okay about that, though; I was willing by then to just sit back and let the words go by, which I suppose indicates little conviction of the relevance despite a compulsion to read through to the end. For whatever that's worth!)
Confirms anything and everything you always knew about the corrupt roots of Western pill-pushing medicine. To understand where we are going, you need to understand were we've been. I was especially interested to see how the animinstic old-world religion ideologies were much more acceptable and commonly held until much later.