“Mysticism” refers to a method or series of methods for arriving at what is believed to be non-sensory awareness of the ordinarily hidden causes, underlying principles, and ultimate facts of truths of existence, as well as the ordinarily hidden “levels” of existence within and beyond oneself.
“Gnosis” is a Greek term that I take to refer to nonsensory awareness of the ordinarily hidden causes, underlying principles, and ultimate facts or truths of existence, as well as the ordinarily hidden “levels” of existence within and beyond oneself. It is distinguished from “episteme,” or knowledge in the ordinary sense rooted in sensory (or even extrasensory) experience and the rules of logic. (And I of course would not refer to propositions based on gnosis or sensory experience and the rules of logic as knowledge; I would instead use the term apparently justified belief.)
“Zen” is the Japanese translation of the Chinese term “Chan,” which in turn is a translation of the Sanskrit word “Dhyana.” I take this word to mean “meditative absorption,” that is, concentration that reaches the point where there is no experienced distinction between the subject or perceiver and the object perceived, or in other words where there is no subject-object duality.
“Satori” is one name for pure awareness, in which what were once distinguished as subject and object are both experienced as objects of consciousness.
There is a state of awareness beyond even satori, wherein neither subject nor object arises at all, where there is only naked awareness. It is possible to abide in this naked awareness continuously. I will refer to this state as “boundlessness” or “the boundless.” At times, I may also refer to this state as “Ati.”
“Shamanism” here refers not to the specific traditions of Mongol, Altaic, and Siberian ethnic groups which have specialists who utilize a technique of ecstasy for communicating with and channeling what they believe to be nonphysical conscious beings (or spirits) and visiting realms of existence hidden from the physical senses and everyday experience in general, but to this technique itself and to the similar (though usually not identical) techniques found elsewhere on Earth.
“Wisdom” refers to sustained, absorptive insight into the underlying causes and principles and ultimate facts or truths of existence, and — most importantly — living in accordance with such insight.