UNIVERSE OF ASIYAH (MAKING)
There are four Universes, Atzilut (Nearness), Beriyah (Creation), Yetzirah (Formation), and Asiyah (Making).
The prophets were able to see into Atzilut even though it was shrouded in the light of Beriyah. Ezekiel himself received his prophecy through Atzilut clothed in the light of Beriyah which was itself clothed in Yetzirah.
I know that sounds really really confusing but it merely means the prophets peered into the other realms of existence through a lense. See, the human mind never gazes directly upon the Glory of G-d. Normally Divine revelations come to humans through angels like Metatron or Akhteriel.
There are plenty of occultists who have gone mad while working through the various paths of Kabbalah. I've always believed that this happened because they were power hungry and had twisted desires in their heart but now I'm not so sure.
Rabbi Chaim Vital explained the practical kabbalah in a way I find incredibly interesting:
"From then on, people only made use of techniques involving the universe of Asiyah. since this is the lowest of the universes, it's angels have only a little good, and are mostly evil. Besides this, this is a level where good and evil are closely intertwined and it's very difficult to separate them. This does not bring any enlightenment since it's impossible to perceive good alone, and one's perception is therefore a combination of good and evil, truth and falsehood."
"Besides this, it involves coercing angels with oaths against their will. These angels retaliate by enticing the individual, drawing them into evil ways until his soul is destroyed."
Now, I've studied quite a few grimoires, The Testament of Solomon being chief among them. In this text one finds specific instructions on binding certain spirits through use of angels from the higher realms.
Think of Edward Kelley for a moment. He was a good friend of John Dee and undoubtedly a very well mastered Quaballist. Now this man went absolutely mad deciphering the language of the angels, the famous Enochian Keys.
Could it be that he peered into what jewish mystics call Asiyah and fell prey to a nefarious being? If so, how many of the intentional blinds we find in Crowley's work or Fortunes were actually put their by them?
I say this because it never occurred to me to actually act on any of the teachings in the grimoires. I've always relied heavily on Ru'ahh to guide my higher self safely through the other realms. It puts a whole new spin on that "to dare" mantra.
Either way, I highly recommend speculative study and meditation before diving in the deep end of the pool. Just food for thought.