One of psychologies’ earliest practitioners was Dr. William James PhD., (1842 – 1910). He established psychology’s department at Harvard and identified the following four main characteristics of mystical experiences, given here in summary:
Ineffability. Experiences beyond words. He said mystical experiences have to be experienced to be understood. This word is still in use by some modern scholars and physicists who otherwise presumbly dare not risk their reputations in outright declaration of their accceptance of the revelatory mystic phenomenon.
Noetic quality. The experiences give cosmic knowing, insights into existence. Experiencers (mystics) acquire a knowledge of infinite intelligence, as well as of an infinitely huge presence, a power of non human reality otherwise unknown to man. (And non-biological, religious or idealogical in my case).
Transiency. Mystical experiences are usually brief though their influence is permanent. (In a state of continuing development of the mystic in my experience).
Passivity. “The mystic feels as if his own will were in abeyance” or “as if he were grasped and held by a superior power.” (Hence my certainty that Reality Rules!).
William James. The Varieties of Religious Experience. 1958.
Types of Mystical Experiences.
Mystical Experiences of Reality 
The book made a huge impression on me when I read it 30 years ago. These days I find the antiquated language quite a struggle but might try again. Just finished Walden which is also a struggle – how the language has changed in the 150+ years since it was written.
William James wrote his lectures around 1900 and these days his style and use of language seems very antiquated.
LikeLike
Yes, i was so astounded and relieved with my discovery of this eminent thinker’s confirmation of what I thought were only my own, secret, exclusive personal experiences, that was the moment I discovered males can cry, can fall on their knees, cover their faces and sob uncontrollably. Catharsis in excelsis!
Best regards, Keith.
LikeLiked by 1 person