William James' four characteristics of mystical experience

Ineffability

• 'The subject of it immediately says that it defies expression, that no adequate report of its contents can be given in words'
• The mystical experience is so profound that mundane language cannot express it

Noetic quality

• 'Mystical states seem to those who experience them to be also states of knowledge. They are states of insight into depths of truths... all inarticulate though they remain; and as a rule they carry with them a curious sense of authority for after-time'
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