Again great piece of work from Gregor Maehle, this time in his latest book, he gives us a beautiful and complete description and explanation of spiritual evolution, nothing less than a map of transformative states as he calls it. Brilliant work linking this spiritual evolution to the activation of chakras in the complex human mechanism. Gregor shows us how one can activate those chakras either through taking drugs or through the safer and more efficient yogic techniques. I highly recommend this must-read for anyone passionates by spiritual evolution, for yogis who wants to deepen the understanding of their practice and for Yoga teachers who wants to enhance their skills and be able to offer safer and more science-based, evidence-based classes to their students. Namaste, Eric.