From Pat Deveney's journal database:

Mentation.
Cogito ergo sum / To Make Spiritual Truth An Effective Force For Ordered Freedom and Common Good
1963 Quarterly
Playa del Rey, CA.
Language: English.
Editor: Robert Achzehner.
Publisher: The High Watch, The Prosperos.
Succeeds: The Prosperos Newsletter
1/1, 1963. 32 pp., 50 cents a year.

This was the organ of The Prosperos, a group founded on the enlightenment received by Thane Walker in, as he said, the bar of the Harvard Club in 1956 after listening to lectures by Lewis Mumford. He based his work on the works of Emma Curtis Hopkins, George I. Gurdjieff, Emmett Fox, Freud and Krishnamurti. The group offered "a transformative spiritual education" that merged modern psychology, astrology and sexual ideas, primarily homosexuality. On the group, see the note under The Prosperos.