James's Four Marks

The philosopher and psychologist William James, in his 1902 Gifford Lectures published as The Varieties of Religious Experience, undertook one of the earliest systematic attempts to study religious and mystical experience empirically, examining first person accounts across traditions rather than beginning from theological doctrine, and proposed four marks by which a genuinely mystical state of consciousness could be identified. Ineffability names the reported quality that the experience defies adequate description in ordinary language, that a person who has had one insists it must be directly experienced rather than communicated.

Noetic quality names the sense, reported across many such accounts, that the experience delivers a form of genuine knowledge or insight rather than mere feeling, however hard that insight is to state afterward. Transiency names the typically brief duration of the state, rarely sustained for long, and passivity names the sense reported by mystics that the experience happens to them, taking hold of the person rather than being produced by their own deliberate effort, even where preparatory practice such as prayer or meditation preceded it. James treated these four marks as descriptive rather than doctrinal, a psychological profile drawn from testimony across many religious traditions rather than an argument for the truth of any one of their specific theological claims.