Tertium Organum

Tertium Organum: The Third Canon of Thought, a Key to the Enigmas of the World is a book by P. D. Ouspensky, first published in 1912. A daring experiment in thought, this work argues that ordinary logic and everyday perception are inadequate for understanding reality. Moving between mysticism, mathematics and modern science, the book proposes a new “third” canon of thought that foregrounds higher dimensions, the limits of linear reasoning, and the possibility of different states of consciousness.

Written in a style that blends essay, philosophical reflection and speculative geometry, it invites readers to re-evaluate time, space and the conventions that shape perception. Practical and provocative by turns, the book went on to influence twentieth-century esoteric and philosophical circles by proposing a synthesis of Eastern and Western traditions with contemporary scientific ideas. It is often read by students of metaphysics, higher-dimensional theory, occult philosophy and anyone drawn to works that challenge the assumptions of classical and positivist thought. This is a 1922 translation by Nicholas Bessaraboff and Claude Bragdon.