While his writing style may have made him seem crazy, his information is accurate. Now we can of course debate whether we agree with it, but as someone who has studied metaphysics for over 10 years, there is evidence in sacred scripture to at least back up his claims. Look at Corinthians 1:12 in the Bible, concerning spiritual gifts. Cross-reference this with Patanjali's famous text, the Yoga Sutras, where he describes the 'siddhis', or spiritual abilities one can gain on the spiritual path. Both east and west discuss these topics, so we should at least remain open-minded before judging, imho.